Re: [gentoo-user] Re: My system startup (was More on fbuffer andgrub setup)
Ow Mun Heng wrote: >On Thu, 2005-03-31 at 20:51 +0200, Richard Fish wrote: > > >>Long answer: >>Sager NP5680...3Ghz P4/w HT, 512k L2 cache, 800Mhz FSB, 1GB RAM, 2 >>Hitachi 60Gb 7200rpm drives, DVD+/-R/RW. It weighs around 11-12 lbs >> >> > >That's a Heavy laptop. Big A$$ too. Since it's a P4 Desktop processor at > > Yeah, but it is a lightweight compared to its replacement that I will be buying late this year: http://www.sagernotebook.com/pages/notebooks/product.cfm?ProductType=9860 >Definately. And since you're running on 7200rpm Drives, it's way better >than my 5400. Depending on the location of your drives, don't it becomes >unbearably hot?? (mine's on the left Wrist pad which makes it ultra hot >esp after a long backup session) > > Similar problem, my drives are under the right wrist. I definitly notice a warming sensation during a 2-hour full-system backup. But it is not much worse than 5400rpm drives...if you check the manufacturer specs you will probably find that they consume only slightly more power and dissipate slightly more heat than most 5400rpm drives. The only bad thing in the NP5680 is that the two drives are stacked on top of each other, with no ventilation, so if I don't use my laptop cooler that blows air on the underside of the laptop, the top drive can get pretty hot (up to 55C according to hddtemp). With the cooler there and running, they never top 50C, and mostly stay around 40C. It is certainly more comfortable than laying my left hand next to the laptop though...that is where the CPU exhaust goes, and when the system is busy, it makes a great coffee warmer! >I'll have to see how it fares for me. Hope there isn't a big learning >curve for this. > > Well, it can be a lot of work unfortunately, especially if you decide to encrypt your root filesystem, because then you really need a custom boot CD (unless someone knows of one that already supports loop-AES?). But if you leave root unencrypted, you don't have to worry about your system just not booting, you might just lose access to your personal files while you figure out what got messed up. The biggest risk is that if you lose your encrypted key file, well, your data is essentially gone. So make sure you have your key file (systemkey.gpg in my example) in multiple physical locations, and don't forget the password (obviously!). -Richard -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Re: My system startup (was More on fbuffer andgrub setup)
On Thu, 2005-03-31 at 20:51 +0200, Richard Fish wrote: > Ow Mun Heng wrote: > >[Big SNIP] > >your explanation seems logical but I won't know until I tried it out. > >Before I do that, I just need to ask. > > > >1. What laptop > >2. CPU/RAM/HD motor speed. > > > > > > Short answer: > I would suggest to emerge aespipe and measure the performance with it. > That should give you a good hint as to what your system is capable of > with loop-AES. I'm gonna try that out. I'm also paranoid. (but seems like you beat me hands down. Kidding) > Long answer: > Sager NP5680...3Ghz P4/w HT, 512k L2 cache, 800Mhz FSB, 1GB RAM, 2 > Hitachi 60Gb 7200rpm drives, DVD+/-R/RW. It weighs around 11-12 lbs That's a Heavy laptop. Big A$$ too. Since it's a P4 Desktop processor at 3GB. Mine's only a Pentium M 1.4G w/512MB Ram (hoping to upgrade to 1stick 1GB to make it 1256MB) > I think seek time and > IOs/sec are much more important in the laptop than throughput. It just Definately. And since you're running on 7200rpm Drives, it's way better than my 5400. Depending on the location of your drives, don't it becomes unbearably hot?? (mine's on the left Wrist pad which makes it ultra hot esp after a long backup session) > > WIth multi-key loop-AES, my processor can encrypt/decrypt data at about > 80MB/sec. In single key mode, it runs at about 110-120MB/sec (I had to I'll have to see how it fares for me. Hope there isn't a big learning curve for this. > But I don't notice any significant latency or lag compared to when I ran > without encryption. The system boots normally (password to KDE login > takes 30-45 seconds, depending upon whether the network is connected or > not, KDE3.4 starts up in a flash, OOo...well...it starts...eventually. > Emerging is disk-bound on extraction and installation, but CPU-bound on > compiling, so there is no noticable lag there. > Dude.. P4 3GHz. SHould be worth the Moolah for that. > I don't know how a Pentium-M would perform. I've read a review > somewhere that basically said the P-M is faster at some things in Linux > due to the increased cache size, but slower in other things, because gcc > treats it as just a regular P4, without taking advantage of any of the > special P-M instructions. YMMV. If you have one and do some tests, I > would be interested in the results. Yeah.. I'll do the aespipe test on it. D600 + 1.4G Centrino + 512MB Ram + 80GB Hitachi 5400rpm 8MB Cache Let you know later > > > Geez, another huge email from me. This is becoming a habit. :-) > > -Richard > > -- > gentoo-user@gentoo.org mailing list -- Ow Mun Heng Gentoo/Linux on DELL D600 1.4Ghz 98% Microsoft(tm) Free!! Neuromancer 15:17:45 up 19:13, 6 users, load average: 0.12, 0.21, 0.18 -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Re: My system startup (was More on fbuffer andgrub setup)
Ow Mun Heng wrote: >Wow.. This is a long post. :-D > > > Yep, If I had personal web pages up and running again, I would have written it up there, and just posted a link. ;-> >[Big SNIP] >your explanation seems logical but I won't know until I tried it out. >Before I do that, I just need to ask. > >1. What laptop >2. CPU/RAM/HD motor speed. > > Short answer: I would suggest to emerge aespipe and measure the performance with it. That should give you a good hint as to what your system is capable of with loop-AES. I have also tried dm-crypt (yes, recently), and found the performance to be slower, and the setup was a pain, particularly for encrypting the root volume. He may not be popular on lkml, but Jari Russo did a nice job with loop-AES. Long answer: Sager NP5680...3Ghz P4/w HT, 512k L2 cache, 800Mhz FSB, 1GB RAM, 2 Hitachi 60Gb 7200rpm drives, DVD+/-R/RW. It weighs around 11-12 lbs including the power adapter, which I need to have everywhere because the battery will only last 30-60 minutes. It certainly doesn't make it through your typical business meeting. But it is perfect for me, and at 18 months old, and I am already yearning for a newer, faster, (and heavier) laptop! Before I start spouting a bunch of numbers, I should mention that I don't really consider maximum sustained throughput to be a good indication of overall hard disk performance. I think seek time and IOs/sec are much more important in the laptop than throughput. It just so happens that the disk with the fastest throughput is also the one with the lowest seek time and highest IOs/sec. It is also the only sensible benchmark for encryption performance. Keep in mind most of these numbers are from my memory. Check your favorite hardware site if you want real benchmarks with attributable sources! Each hard drive can sustain throughput from 40MB/sec on the outside edge down to 20MB/sec on the inside (Avg ~29MB/sec). (My 5400rpm drives range from 34-17MB/sec). The RAID0 array throughput runs something like 70-35MB/sec. WIth multi-key loop-AES, my processor can encrypt/decrypt data at about 80MB/sec. In single key mode, it runs at about 110-120MB/sec (I had to measure this with aespipe. Loop-AES is disk-bound for me.) My choice is single key mode, because I am mostly concerned with someone stealing my laptop and then taking advantage of the financial data or identity information on it. There is also some confidential work and client data, but nothing of the sort that you could not also find on a typical home desktop PC. So, I am able to achieve 'real-time' encryption, except for one case: when I make a backup of my system (using external USB2.0 hard disks, also encrypted), my system has to decrypt the data from the main drives, compress it (using the equivalent of gzip -1), and then re-encrypt the data for writing to the external disks. A full system backup is obviously a CPU-bound process for me. Still, I am able to average 12-15MB/sec for my backups, and I should note that the backup drives max out at 20MB/sec (a 'feature' of the USB/IDE bridge). The biggest downside in using encryption on my laptop is that if I am doing something that really wants a lot of disk bandwidth, it also uses a lot of CPU time. Pure disk access will use up to 60-80% of my processor. And on my laptop, that translates directly into the CPU fans spinning up to faster speeds, making more noise, with more heat being dumped out the side. Good for keeping coffee warm, bad for battery life. But I don't notice any significant latency or lag compared to when I ran without encryption. The system boots normally (password to KDE login takes 30-45 seconds, depending upon whether the network is connected or not, KDE3.4 starts up in a flash, OOo...well...it starts...eventually. Emerging is disk-bound on extraction and installation, but CPU-bound on compiling, so there is no noticable lag there. I don't know how a Pentium-M would perform. I've read a review somewhere that basically said the P-M is faster at some things in Linux due to the increased cache size, but slower in other things, because gcc treats it as just a regular P4, without taking advantage of any of the special P-M instructions. YMMV. If you have one and do some tests, I would be interested in the results. Geez, another huge email from me. This is becoming a habit. -Richard -- gentoo-user@gentoo.org mailing list
