Re: [Hampshire] [OT] memory sticks
2009/3/18 Lisi : > What are the relative advantages and disadvantages of two pairs of sticks > given that they both cost the same? > Basically, why one might prefer: > CT2KIT12864AA667 • DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • > 1.8V • 128Meg x 64 > to: > CT2KIT12864AA800 • DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • > 1.8V • 128Meg x 64 > or vice versa. > If this is to add to a system that already had memory, I would advise picking the one that most closely matched the memory already present. There should be a way to tell if the current memory in PC2-5300 or PC2-6400. This is because some motherboards cannot handle different speeds of memory at once. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] [OT] memory sticks
2009/3/18 Hugo Mills : > On Wed, Mar 18, 2009 at 11:04:53PM +, Adrian Bridgett wrote: >> > Basically, why one might prefer: >> > CT2KIT12864AA667 • DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • >> > 1.8V • 128Meg x 64 >> > to: >> > CT2KIT12864AA800 • DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • >> > 1.8V • 128Meg x 64 >> Second one is a tad faster, not that you are likely to notice any >> difference at all. > > Higher bandwidth, but the same latency -- it takes one more clock > cycle to find a page on the higher-rated unit, although it works out > as pretty much exactly the same wall-clock time (7.5ns), because the > clock rate is faster. > > Hugo. where the 7.5 ns is got from : the 6 (in CL=6) times 1.25 ns, and 1.25 * 10^-9 is 1 second divided by the 800 (from the DDR-800 and also the AA800 phrase). So for the other stick, latency is 10^9 / 667 = 1.5 MHz, times 5 cycles, also = 7.5 ns. And higher bandwidth because once the pipelines are primed the 800MHz chip pumps the data through at a higher rate. -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] [OT] memory sticks
On Wednesday 18 March 2009 23:08:30 Alan Bell wrote: > this bit is the speed rating: > PC2-6400 > PC2-5300 > and the 6400 one is faster. If your computer doesn't support PC2-6400 it > should just operate at 5300 speeds. In fact the 800 and the 667 is the > speed in Mhz I think. Not always true however. I had an issue recently with an old server which could handle 2 DIMMS of faster memory fine, but couldn't cope with 4 of the same. -- Be seeing you, http://www.glendale.org.uk Sam.Mail/IM (Jabber): s...@glendale.org.uk -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] [OT] memory sticks
On Wed, Mar 18, 2009 at 11:04:53PM +, Adrian Bridgett wrote: > On Wed, Mar 18, 2009 at 20:42:03 + (+), Lisi wrote: > > What are the relative advantages and disadvantages of two pairs of sticks > > given that they both cost the same? > > Basically, why one might prefer: > > CT2KIT12864AA667 • DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • > > 1.8V • 128Meg x 64 > > to: > > CT2KIT12864AA800 • DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • > > 1.8V • 128Meg x 64 > > or vice versa. > > Second one is a tad faster, not that you are likely to notice any > difference at all. Higher bandwidth, but the same latency -- it takes one more clock cycle to find a page on the higher-rated unit, although it works out as pretty much exactly the same wall-clock time (7.5ns), because the clock rate is faster. Hugo. -- === Hugo Mills: h...@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- "I lost my leg in 1942. Some bastard stole it in a --- pub in Pimlico." signature.asc Description: Digital signature -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] [OT] memory sticks
this bit is the speed rating: PC2-6400 PC2-5300 and the 6400 one is faster. If your computer doesn't support PC2-6400 it should just operate at 5300 speeds. In fact the 800 and the 667 is the speed in Mhz I think. Alan. Lisi wrote: > What are the relative advantages and disadvantages of two pairs of sticks > given that they both cost the same? > Basically, why one might prefer: > CT2KIT12864AA667 • DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • > 1.8V • 128Meg x 64 > to: > CT2KIT12864AA800 • DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • > 1.8V • 128Meg x 64 > or vice versa. > > http://www.crucial.com/uk/store/listparts.aspx?model=K8M890M2MB-RS2H&pl=FOXCONN&cat=RAM > (the first two pairs of sticks) > The processor is an AMD Athlon 64 3500+. > > TIA > Lisi > > -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
Re: [Hampshire] [OT] memory sticks
On Wed, Mar 18, 2009 at 20:42:03 + (+), Lisi wrote: > What are the relative advantages and disadvantages of two pairs of sticks > given that they both cost the same? > Basically, why one might prefer: > CT2KIT12864AA667 • DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • > 1.8V • 128Meg x 64 > to: > CT2KIT12864AA800 • DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • > 1.8V • 128Meg x 64 > or vice versa. Second one is a tad faster, not that you are likely to notice any difference at all. Adrian -- Email: adr...@smop.co.uk -*- GPG key available on public key servers Debian GNU/Linux - the maintainable distribution -*- www.debian.org -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
[Hampshire] [OT] memory sticks
What are the relative advantages and disadvantages of two pairs of sticks given that they both cost the same? Basically, why one might prefer: CT2KIT12864AA667 • DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 128Meg x 64 to: CT2KIT12864AA800 • DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • 1.8V • 128Meg x 64 or vice versa. http://www.crucial.com/uk/store/listparts.aspx?model=K8M890M2MB-RS2H&pl=FOXCONN&cat=RAM (the first two pairs of sticks) The processor is an AMD Athlon 64 3500+. TIA Lisi -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --
