Author: Keith Evans
Date: 20:50:10 04/28/03
Go up one level in this thread
On April 28, 2003 at 23:06:56, Aaron Gordon wrote: >On April 28, 2003 at 21:42:51, Keith Evans wrote: > >>On April 28, 2003 at 21:27:34, Aaron Gordon wrote: >> >>>On April 28, 2003 at 21:17:38, Keith Evans wrote: >>> >>>>On April 28, 2003 at 19:47:57, Aaron Gordon wrote: >>>> >>>>>On April 28, 2003 at 15:04:58, Keith Evans wrote: >>>>> >>>>>>On April 27, 2003 at 10:40:10, Aaron Gordon wrote: >>>>>> >>>>>>>On April 27, 2003 at 01:52:41, Keith Evans wrote: >>>>>>> >>>>>>>>On April 27, 2003 at 01:38:15, Aaron Gordon wrote: >>>>>>>> >>>>>>>>>On April 26, 2003 at 22:52:42, Keith Evans wrote: >>>>>>>>> >>>>>>>>>>On April 26, 2003 at 22:25:47, Aaron Gordon wrote: >>>>>>>>>> >>>>>>>>>>>On April 26, 2003 at 21:11:59, Tom Kerrigan wrote: >>>>>>>>>>> >>>>>>>>>>>>I checked Aaron's story with his contact at AMD. The guy said that AMD didn't >>>>>>>>>>>>allow performance testing with the memory _overclocked_, but it certainly isn't >>>>>>>>>>>>underclocked. This makes perfect sense to me. (If you allow overclocking memory, >>>>>>>>>>>>why wouldn't you also overclock the processor? Then all your benchmarks are >>>>>>>>>>>>worthless.) >>>>>>>>>>>> >>>>>>>>>>>>So SPEC is comparing non-overclocked Intel to non-overclocked AMD and Intel >>>>>>>>>>>>wins. >>>>>>>>>>>> >>>>>>>>>>>>-Tom >>>>>>>>>>> >>>>>>>>>>>When I ran the tests I recalled seeing some information where the P4 was running >>>>>>>>>>>CAS2 and the like. The settings I was told to use put me at CAS 2.5. >>>>>>>>>>>How would this be 'fair'? Same thing happens on some review pages, but to a much >>>>>>>>>>>larger degree. As I have proven in the past tomshardware has actually run the >>>>>>>>>>>memory lower than the bus on the athlons tested, put the AGP to 1x, etc. >>>>>>>>>>> >>>>>>>>>>>Also, running CAS2 with all tweaks enabled isn't "overclocking". Especially when >>>>>>>>>> >>>>>>>>>>I think that the main point is that the manager basically was trying to prevent >>>>>>>>>>memory (and maybe other components) from being run out of specification. This is >>>>>>>>>>what I suspected. He probably felt that if AMD ran components out of spec and >>>>>>>>>>quoted the numbers, then Intel could get nasty. >>>>>>>>>> >>>>>>>>>>Your argument is with him. Determining that memory is being run in spec is not >>>>>>>>>>as simple as quoting a single parameter like "CAS 2.5." Download a memory >>>>>>>>>>datasheet, a chipset datasheet, see how the BIOS is programming the chipset, >>>>>>>>>>draw waveforms, and check all of the parameters. It is painful, but anything >>>>>>>>>>else is handwaving. >>>>>>>>> >>>>>>>>>What I'm trying to point out is the ram was Corsair PC2400XMS CL2. Rated for >>>>>>>>>150MHz(300DDR) at CL2.0. I was told to run 133MHz fsb stock (which I have no >>>>>>>>>problems with) and CL2.5, bank interleaving off, other timings slower than usual >>>>>>>>>which IS much below the rams normal speed. >>>>>>>>> >>>>>>>>>Nothing was overclocked, nothing would have been overclocked. Even with maximum >>>>>>>>>timings, the ram would be still running UNDER spec. If you'd like to see for >>>>>>>>>yourself, here is the PC2400XMS CL2 datasheet from Corsair. >>>>>>>>> >>>>>>>>>http://www.corsairmicro.com/main/products/specs/cm64sd256.pdf >>>>>>>>> >>>>>>>>>The numbers off of the dimm = CM64SD256-2400C2 >>>>>>>>> >>>>>>>>>If for some reason you'd like to see the DIMM, go here.. >>>>>>>>>http://www.newageoc.com/pics2/corsair2400cl2.jpg >>>>>>>> >>>>>>>>Then the question remains, why did the manager apparently believe that something >>>>>>>>would be operating out of spec? That corsair datasheet doesn't have enough >>>>>>>>detail. See page 50 and associated diagrams in the following: >>>>>>>> >>>>>>>>http://download.micron.com/pdf/datasheets/dram/128Mx4x8x16DDR_D.pdf >>>>>>>> >>>>>>>>Regards, >>>>>>>>Keith >>>>>>> >>>>>>>Running 150MHz CL2 ram at 133MHz CL2 isn't going to put it out of spec. >>>>>> >>>>>>Looking at the JPEG that you posted it looks like the part number for the Micron >>>>>>DDR SDRAM is 46V16M8-75B. Without any "Z" after the "75". >>>>>> >>>>>>That part is not rated for 133 MHz CL2 operation, you need to run it with CL=2.5 >>>>>>for 133 MHz. If you want CL=2 then lower the frequency to 100 MHz. >>>>>> >>>>>>This is from the cover sheet of the Micron specification which I posted. >>>>>> >>>>>>If there is a "Z" on the package after the "75" that I missed, then I agree with >>>>>>you. >>>>>> >>>>>>Regards, >>>>>>Keith >>>>> >>>>>So Corsair is selling overclocked ram? The ram itself is rated by Corsair for >>>>>150MHz opteration at CAS-2.0. It runs 166MHz CAS-2.0 (but I consider THAT >>>>>overclocking, not 150MHz CAS-2.0). 133MHz CAS-2.5 would be extreme >>>>>underclocking. It wasn't rated PC2400 CL2 for nothing. >>>> >>>>"So Corsair is selling overclocked ram?" Yes. So it all makes sense. The AMD >>>>manager was not comfortable quoting benchmark results obtained with overclocked >>>>RAM. Nice simple explanation with evidence to back it up. >>>> >>>>Do you slap stickers on the Athlons that you resell quoting higher MHz ratings >>>>than AMD? And then if a mom and pop shop buys them, puts them in a motherboard, >>>>and sells the resulting PC they can say to their customers that it isn't >>>>overclocked because newageoc rates them at the higher speed? >>>> >>>>This is a no brainer. >>> >>>From everything I've seen you'll get pretty nasty lawsuits if you overclock >>>something, sell it for more and don't specify that it's overclocked. See >>>"remarking". >>> >>>I'm not getting any hell from AMD because people can read plain as day the chips >>>are overclocked. Nowhere in on Corsair's page do they say the modules are >>>"pre-overclocked" and you can almost guarantee Micron would have a heart attack >>>if they did something like that without informing customers. Try emailing both >>>Micron and Corsair on the matter and see what they've got to say about it. >> >>You can call Corsair and ask about getting your money back if you want... >> >>Please point out any mistakes that I have made. Did you download the Micron >>datasheet? Does it confirm what I said? > >All I see are specifications for -75 and -75Z, not -75B. I don't think that the "B" is part of the speed code. Note that there is a large gap between the 75 and the B. Maybe it's a revision code? You can look at: http://download.micron.com/pdf/numbering/numdram.pdf For an overview of DDRAM part numbers. Also see how Micron numbers their own DDRAM modules: http://download.micron.com/pdf/numbering/numdrammod.pdf
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.