Re: Dual Core Or Dual CPU - What's the real difference in performance?
Nicole Harrington wrote: --- Cy Schubert [EMAIL PROTECTED] wrote: In message [EMAIL PROTECTED], Nicole Harrington wri tes: --- Cy Schubert [EMAIL PROTECTED] wrote: In message [EMAIL PROTECTED], Mike Meyer writes: Generally, more processors means things will go faster until you run out of threads. However, if there's some shared resource that is the bottleneck for your load, and the resource doesn't support simultaneous access by all the cores, more cores can slow things down. Of course, it's not really that simple. Some shared resources can be managed so as to make things improve under most loads, even if they don't support simultaneous access. Generally speaking the performance increase is not linear. At some point there is no benefit to adding more processors. In a former life when I was an MVS systems programmer the limit was seven processors in a System/370. Today we can use 16, 32, even 64 processors with a standard operating system and current hardware, unless one of the massively parallel architectures is used. To answer the original posters question, there are architectural differences mentioned here, e.g. shared cache, I/O channel, etc., but the reason the chip manufacturers make them is that they're more cost effective than two CPUs. The AMD X2 series of chips (I have one), they're not truely a dual processor chip. They're analogous to the single processor System/370 with an AP (attached processor) in concept. What this means is that both processors can execute all instructions and are just as capable in every way except external interrupts, e.g. I/O interrupts, are handled by the processor 0 as only that processor is wired to be interrupted in case of external interrupt. I can't comment about Intel's Dual Core CPUs as I don't know their architecture but I'd suspect the same would be true. Chips in which there are two dual core CPUs on the same die, I believe one of each of the dual core CPUs can handle external interrupts. Wow I love ansking questions without too many specifics as I learn so much more. With this however it really seems to be a love hate relationship with dual core. Based on what you stated above, would that mean that when using a dual core system, using polling interupts might be better or perhaps monumanally worse? No. CPU 0 would be interrupted. It would schedule the interrupt in the queue. Either CPU could service the interrupt once the interrupt was queued. Some devices need to be polled as they do not generate interrupts or they generate spurious interrupts. Otherwise allowing a device to interrupt the CPU is more efficient as it allows the CPU to do other work rather than spinning its wheels polling. This is the Von Neumann model. -- Cheers, Cy Schubert [EMAIL PROTECTED] FreeBSD UNIX: [EMAIL PROTECTED] Web: http://www.FreeBSD.org e**(i*pi)+1=0 Yes, I have heard that, thanks. However, how does one know or tell which is the right mode/model for which devices? I have seen people on either side (poll vs interupt) claim one is better or much like an infomercial, just do blah and your system will be so much faster. Altho of course that would be the pro polling side, since by default, interupts are used. Is it all just imperical testing? Take this pill and see let me know how you feel? It seems as though when it's heavy networking, use polling. Otherwise stick with interupts. I have even heard when using X network card, use polling. How would know when one card will do better with polling while another may not? Thanks for helping me understand the debate better. Nicole Nicole: If you're doing something regularly, no matter what the task, polling is the better method. Interrupts are for cases when you do something occasionally, but not all the time over your clock cycle. It's really dependent on the situation and the use of the software, for when interrupts are better than polling. Not sure how AMD does it over Intel, but different things are done in different ways in either chipmaker camp, so interrupts may be better with AMD, than with Intel (I'm just thinking pipeline length because Intel's always had long pipelines in their processors). Anyhow, best of luck deciding with method is better, although depending on your situation it probably doesn't matter all that much, esp since there are other limiting factors in the system like bus speed, harddrives, chipset speed, etc. Just basing the factors off CPUs is a bad way to go as it's not a complete analysis. Cheers, -Garrett ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
--- Cy Schubert [EMAIL PROTECTED] wrote: In message [EMAIL PROTECTED], Nicole Harrington wri tes: --- Cy Schubert [EMAIL PROTECTED] wrote: In message [EMAIL PROTECTED], Mike Meyer writes: Generally, more processors means things will go faster until you run out of threads. However, if there's some shared resource that is the bottleneck for your load, and the resource doesn't support simultaneous access by all the cores, more cores can slow things down. Of course, it's not really that simple. Some shared resources can be managed so as to make things improve under most loads, even if they don't support simultaneous access. Generally speaking the performance increase is not linear. At some point there is no benefit to adding more processors. In a former life when I was an MVS systems programmer the limit was seven processors in a System/370. Today we can use 16, 32, even 64 processors with a standard operating system and current hardware, unless one of the massively parallel architectures is used. To answer the original posters question, there are architectural differences mentioned here, e.g. shared cache, I/O channel, etc., but the reason the chip manufacturers make them is that they're more cost effective than two CPUs. The AMD X2 series of chips (I have one), they're not truely a dual processor chip. They're analogous to the single processor System/370 with an AP (attached processor) in concept. What this means is that both processors can execute all instructions and are just as capable in every way except external interrupts, e.g. I/O interrupts, are handled by the processor 0 as only that processor is wired to be interrupted in case of external interrupt. I can't comment about Intel's Dual Core CPUs as I don't know their architecture but I'd suspect the same would be true. Chips in which there are two dual core CPUs on the same die, I believe one of each of the dual core CPUs can handle external interrupts. Wow I love ansking questions without too many specifics as I learn so much more. With this however it really seems to be a love hate relationship with dual core. Based on what you stated above, would that mean that when using a dual core system, using polling interupts might be better or perhaps monumanally worse? No. CPU 0 would be interrupted. It would schedule the interrupt in the queue. Either CPU could service the interrupt once the interrupt was queued. Some devices need to be polled as they do not generate interrupts or they generate spurious interrupts. Otherwise allowing a device to interrupt the CPU is more efficient as it allows the CPU to do other work rather than spinning its wheels polling. This is the Von Neumann model. -- Cheers, Cy Schubert [EMAIL PROTECTED] FreeBSD UNIX: [EMAIL PROTECTED] Web: http://www.FreeBSD.org e**(i*pi)+1=0 Yes, I have heard that, thanks. However, how does one know or tell which is the right mode/model for which devices? I have seen people on either side (poll vs interupt) claim one is better or much like an infomercial, just do blah and your system will be so much faster. Altho of course that would be the pro polling side, since by default, interupts are used. Is it all just imperical testing? Take this pill and see let me know how you feel? It seems as though when it's heavy networking, use polling. Otherwise stick with interupts. I have even heard when using X network card, use polling. How would know when one card will do better with polling while another may not? Thanks for helping me understand the debate better. Nicole --- If you make people think they're thinking, they'll love you; but if you really make them think, they'll hate you. -- Don Marquis ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
On Wed, Feb 07, 2007 at 07:22:26PM -0800, Garrett Cooper wrote: Andrew Hammond wrote: On 2/7/07, Nicole Harrington [EMAIL PROTECTED] wrote: Hello all, I have been building/using servers that were dual CPU AMD Opteron systems for some time. (usually 246 Opteron cpu's) Now of course the world is shifting to Dual Core. Using FreeBSD, what is really the difference, besides power and ability to shove in more memory, between having the two seperate CPUS's? Well, you also have two additional HT buses for memory access. And one additional HT bus for peripheral access although most motherboard manufacturers don't actually do anything with it. What if I did 2, Dual Core cpu's? Would the SMP overhead and sharing to a [Giant Locked] disk and or network erase any benefits? Benefits to what? Your computer can idle quite effectively with a 386 processor while consuming less power, producing less heat and requiring much less capital outlay than any Opteron box. I'm not sure where you got that info, but for the Pentium processor line at least, you're MUCH better off getting a Core Duo compared to the Pentium 4 HT enabled equivalent. I think you took his intended humor too seriously. His point really was that the poster did not indicate what the system would be used for and thus it was not really possible to say much about the benefit. If the system was mostly sitting idle, one CPU is about the same as another CPU in so far as what it gets done. But if it has a load that distributes well over dual cores, then it makes a very big difference. jerry Intel's power system (at least at the hardware level) is pretty good about shutting down cores when not in use, and actually it's better power wise to get a dual core processor compared to a dual processor machine, since on a dual processor machine both processors are fired up at the same time. Besides, with dual cores it's a shorter path electrically core to core, compared to a processor. The only OS that actually performs better with a dual single core processor setup compared to a single dual core processor would be Mac OSX (believe it or not). But that's because they use a mach kernel instead of a monolithic kernel like FreeBSD, Linux, and Windows. Look up previous discussions on this list for the mach kernel and OSX if you're curious, or just look up the article on wikipedia. -Garrett ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
In message [EMAIL PROTECTED], Mike Meyer writes: Generally, more processors means things will go faster until you run out of threads. However, if there's some shared resource that is the bottleneck for your load, and the resource doesn't support simultaneous access by all the cores, more cores can slow things down. Of course, it's not really that simple. Some shared resources can be managed so as to make things improve under most loads, even if they don't support simultaneous access. Generally speaking the performance increase is not linear. At some point there is no benefit to adding more processors. In a former life when I was an MVS systems programmer the limit was seven processors in a System/370. Today we can use 16, 32, even 64 processors with a standard operating system and current hardware, unless one of the massively parallel architectures is used. To answer the original posters question, there are architectural differences mentioned here, e.g. shared cache, I/O channel, etc., but the reason the chip manufacturers make them is that they're more cost effective than two CPUs. The AMD X2 series of chips (I have one), they're not truely a dual processor chip. They're analogous to the single processor System/370 with an AP (attached processor) in concept. What this means is that both processors can execute all instructions and are just as capable in every way except external interrupts, e.g. I/O interrupts, are handled by the processor 0 as only that processor is wired to be interrupted in case of external interrupt. I can't comment about Intel's Dual Core CPUs as I don't know their architecture but I'd suspect the same would be true. Chips in which there are two dual core CPUs on the same die, I believe one of each of the dual core CPUs can handle external interrupts. From an operating system perspective an AP means that processor 0 will receive the interrupt and put it on it's queue. Then either processor 0 or processor 1 would take the interrupt off the queue and do something with it. To add another dimension to this discussion, hyperthreading uses spare cycles in a single processor to pretend there are two processors, increasing performance for some apps and reducing performance for other apps. For example Sun T2000 systems have multiple CPUs each with multiple cores and each core capable of hyperthreading, presenting to Solaris 32 processors where in fact there are only two CPU chips (I may have the numbers wrong as I spend most of my time in management mode at work and you know managers don't have brains). Generally speaking, dual core is an inexpensive way to get SMP into the hands of people who could not normally afford SMP technology as it was. I have a mortgage so spending money on computers is not a high priority in relation to that priority but dual core does give me an opportunity to enter the market relatively inexpensively and get good value for the money I spend on the technology. That's really what it's all about, how much performance you get for the money you spend. -- Cheers, Cy Schubert [EMAIL PROTECTED] FreeBSD UNIX: [EMAIL PROTECTED] Web: http://www.FreeBSD.org e**(i*pi)+1=0 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
In [EMAIL PROTECTED], Cy Schubert [EMAIL PROTECTED] typed: In message [EMAIL PROTECTED], Mike Meyer writes: Generally, more processors means things will go faster until you run out of threads. However, if there's some shared resource that is the bottleneck for your load, and the resource doesn't support simultaneous access by all the cores, more cores can slow things down. Of course, it's not really that simple. Some shared resources can be managed so as to make things improve under most loads, even if they don't support simultaneous access. Generally speaking the performance increase is not linear. At some point there is no benefit to adding more processors. When some other resources becomes the bottleneck. Which resource depends on the workload. In some cases, adding processors will slow things down. To add another dimension to this discussion, hyperthreading uses spare cycles in a single processor to pretend there are two processors, increasing performance for some apps and reducing performance for other apps. I think hyperthreading gets a bad rap. It shares lots of resources - like the computing units - so there are lots of workloads that cause things to get worse when you add a processor. But the general case should still be that it gets faster. Generally speaking, dual core is an inexpensive way to get SMP into the hands of people who could not normally afford SMP technology as it was. Gee, I thought it was a reaction to losing the clock rate war. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
--- Cy Schubert [EMAIL PROTECTED] wrote: In message [EMAIL PROTECTED], Mike Meyer writes: Generally, more processors means things will go faster until you run out of threads. However, if there's some shared resource that is the bottleneck for your load, and the resource doesn't support simultaneous access by all the cores, more cores can slow things down. Of course, it's not really that simple. Some shared resources can be managed so as to make things improve under most loads, even if they don't support simultaneous access. Generally speaking the performance increase is not linear. At some point there is no benefit to adding more processors. In a former life when I was an MVS systems programmer the limit was seven processors in a System/370. Today we can use 16, 32, even 64 processors with a standard operating system and current hardware, unless one of the massively parallel architectures is used. To answer the original posters question, there are architectural differences mentioned here, e.g. shared cache, I/O channel, etc., but the reason the chip manufacturers make them is that they're more cost effective than two CPUs. The AMD X2 series of chips (I have one), they're not truely a dual processor chip. They're analogous to the single processor System/370 with an AP (attached processor) in concept. What this means is that both processors can execute all instructions and are just as capable in every way except external interrupts, e.g. I/O interrupts, are handled by the processor 0 as only that processor is wired to be interrupted in case of external interrupt. I can't comment about Intel's Dual Core CPUs as I don't know their architecture but I'd suspect the same would be true. Chips in which there are two dual core CPUs on the same die, I believe one of each of the dual core CPUs can handle external interrupts. Wow I love ansking questions without too many specifics as I learn so much more. With this however it really seems to be a love hate relationship with dual core. Based on what you stated above, would that mean that when using a dual core system, using polling interupts might be better or perhaps monumanally worse? I have a mortgage so spending money on computers is not a high priority in relation to that priority but dual core does give me an opportunity to enter the market relatively inexpensively and get good value for the money I spend on the technology. That's really what it's all about, how much performance you get for the money you spend. Tring to figure out the fud from reality is often the best way to make sure you really get the best value. However, it always seems to depend on many variables :) Thanks! Nicole -- Cheers, Cy Schubert [EMAIL PROTECTED] FreeBSD UNIX: [EMAIL PROTECTED] Web: http://www.FreeBSD.org e**(i*pi)+1=0 ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-amd64 To unsubscribe, send any mail to [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
In message [EMAIL PROTECTED], Nicole Harrington wri tes: --- Cy Schubert [EMAIL PROTECTED] wrote: In message [EMAIL PROTECTED], Mike Meyer writes: Generally, more processors means things will go faster until you run out of threads. However, if there's some shared resource that is the bottleneck for your load, and the resource doesn't support simultaneous access by all the cores, more cores can slow things down. Of course, it's not really that simple. Some shared resources can be managed so as to make things improve under most loads, even if they don't support simultaneous access. Generally speaking the performance increase is not linear. At some point there is no benefit to adding more processors. In a former life when I was an MVS systems programmer the limit was seven processors in a System/370. Today we can use 16, 32, even 64 processors with a standard operating system and current hardware, unless one of the massively parallel architectures is used. To answer the original posters question, there are architectural differences mentioned here, e.g. shared cache, I/O channel, etc., but the reason the chip manufacturers make them is that they're more cost effective than two CPUs. The AMD X2 series of chips (I have one), they're not truely a dual processor chip. They're analogous to the single processor System/370 with an AP (attached processor) in concept. What this means is that both processors can execute all instructions and are just as capable in every way except external interrupts, e.g. I/O interrupts, are handled by the processor 0 as only that processor is wired to be interrupted in case of external interrupt. I can't comment about Intel's Dual Core CPUs as I don't know their architecture but I'd suspect the same would be true. Chips in which there are two dual core CPUs on the same die, I believe one of each of the dual core CPUs can handle external interrupts. Wow I love ansking questions without too many specifics as I learn so much more. With this however it really seems to be a love hate relationship with dual core. Based on what you stated above, would that mean that when using a dual core system, using polling interupts might be better or perhaps monumanally worse? No. CPU 0 would be interrupted. It would schedule the interrupt in the queue. Either CPU could service the interrupt once the interrupt was queued. Some devices need to be polled as they do not generate interrupts or they generate spurious interrupts. Otherwise allowing a device to interrupt the CPU is more efficient as it allows the CPU to do other work rather than spinning its wheels polling. This is the Von Neumann model. -- Cheers, Cy Schubert [EMAIL PROTECTED] FreeBSD UNIX: [EMAIL PROTECTED] Web: http://www.FreeBSD.org e**(i*pi)+1=0 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Dual Core Or Dual CPU - What's the real difference in performance?
Hello all, I have been building/using servers that were dual CPU AMD Opteron systems for some time. (usually 246 Opteron cpu's) Now of course the world is shifting to Dual Core. Using FreeBSD, what is really the difference, besides power and ability to shove in more memory, between having the two seperate CPUS's? What if I did 2, Dual Core cpu's? Would the SMP overhead and sharing to a [Giant Locked] disk and or network erase any benefits? Thanks! Nicole The Large Print Giveth And The Small Print Taketh Away -- Anon ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
On 2/7/07, Nicole Harrington [EMAIL PROTECTED] wrote: Hello all, I have been building/using servers that were dual CPU AMD Opteron systems for some time. (usually 246 Opteron cpu's) Now of course the world is shifting to Dual Core. Using FreeBSD, what is really the difference, besides power and ability to shove in more memory, between having the two seperate CPUS's? Well, you also have two additional HT buses for memory access. And one additional HT bus for peripheral access although most motherboard manufacturers don't actually do anything with it. What if I did 2, Dual Core cpu's? Would the SMP overhead and sharing to a [Giant Locked] disk and or network erase any benefits? Benefits to what? Your computer can idle quite effectively with a 386 processor while consuming less power, producing less heat and requiring much less capital outlay than any Opteron box. Or did you have a workload in mind? If that's the case then you might want to tell us what it is, what analysis you've done on your current system to figure out where the bottleneck is, and what your performance goals for it are. Andrew ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
Andrew Hammond wrote: On 2/7/07, Nicole Harrington [EMAIL PROTECTED] wrote: Hello all, I have been building/using servers that were dual CPU AMD Opteron systems for some time. (usually 246 Opteron cpu's) Now of course the world is shifting to Dual Core. Using FreeBSD, what is really the difference, besides power and ability to shove in more memory, between having the two seperate CPUS's? Well, you also have two additional HT buses for memory access. And one additional HT bus for peripheral access although most motherboard manufacturers don't actually do anything with it. What if I did 2, Dual Core cpu's? Would the SMP overhead and sharing to a [Giant Locked] disk and or network erase any benefits? Benefits to what? Your computer can idle quite effectively with a 386 processor while consuming less power, producing less heat and requiring much less capital outlay than any Opteron box. I'm not sure where you got that info, but for the Pentium processor line at least, you're MUCH better off getting a Core Duo compared to the Pentium 4 HT enabled equivalent. Intel's power system (at least at the hardware level) is pretty good about shutting down cores when not in use, and actually it's better power wise to get a dual core processor compared to a dual processor machine, since on a dual processor machine both processors are fired up at the same time. Besides, with dual cores it's a shorter path electrically core to core, compared to a processor. The only OS that actually performs better with a dual single core processor setup compared to a single dual core processor would be Mac OSX (believe it or not). But that's because they use a mach kernel instead of a monolithic kernel like FreeBSD, Linux, and Windows. Look up previous discussions on this list for the mach kernel and OSX if you're curious, or just look up the article on wikipedia. -Garrett ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
Nicole Harrington wrote: Hello all, I have been building/using servers that were dual CPU AMD Opteron systems for some time. (usually 246 Opteron cpu's) Now of course the world is shifting to Dual Core. Using FreeBSD, what is really the difference, besides power and ability to shove in more memory, between having the two seperate CPUS's? What if I did 2, Dual Core cpu's? Would the SMP overhead and sharing to a [Giant Locked] disk and or network erase any benefits? Thanks! Nicole Dual core or Quad Core CPUs performance are far better compared to more socket CPUs since they get shared access to memory cache and reduce memory latency/probing over AMDs hypertransport bus. Anandtech did a pretty good review of AMD 4x4 system which compares 2 AMD dual cores with a single Intel Quad chip, where the Intel chip clearly outperforms consistantly because of this fact. Even when taking Intel out of the equation the benchmarks consistantly show even better performance with less sockets for AMD. http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2879p=6 There appears to be no advantage to having seperate CPU socket systems what so ever. And yes the power usage is also bad, even though this example is a quad setup the fact still carriers over to Dual vs 2 socket CPUs. http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2879p=13 Here we have a Quad AMD setup using a whopping 456watts over Intels Quad 263watt system. Thats a performance per watt difference of 73% if you even choose to see the AMD quad multisocket CPU performance as the same as Intels. Mike ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Dual Core Or Dual CPU - What's the real difference in performance?
In [EMAIL PROTECTED], Michael Vince [EMAIL PROTECTED] typed: Nicole Harrington wrote: Using FreeBSD, what is really the difference, besides power and ability to shove in more memory, between having the two seperate CPUS's? Dual core or Quad Core CPUs performance are far better compared to more socket CPUs since they get shared access to memory cache and reduce memory latency/probing over AMDs hypertransport bus. Of course, it's not really that simple. For one thing, the intel quad core CPUS are two dual core chips in one package, and the two chips don't share internal resources - like cache. So any data in cache is only available to two of the four cpus; if the one of the other two cpus needs that data it'll have to go to the external bus. The AMD quad core package is similar - except they don't put the two chips in the same package, but provide a proprietary high-speed interconnect between them. Also, shared access to the memory cache means - well shared access to the memory cache and the memory behind it. Shared access raises the possibility of contention, which will slow things down. If all four CPUs get a cache miss for different data at the same time, one of them is in for a long wait. Yeah, this isn't very likely under most loads. How likely is it under yours? Generally, more processors means things will go faster until you run out of threads. However, if there's some shared resource that is the bottleneck for your load, and the resource doesn't support simultaneous access by all the cores, more cores can slow things down. Of course, it's not really that simple. Some shared resources can be managed so as to make things improve under most loads, even if they don't support simultaneous access. mike -- Mike Meyer [EMAIL PROTECTED] http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]