Searching for the Memory Holy Grail: Part 1

by Wesley Fink on 7/27/2003 11:13 PM EST
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  • Anonymous User - Sunday, August 31, 2003 - link

    This single/double side/bank issue is very misunderstood. To further confuse things the memory manufacturers, who finally getting better about reporting full timing numbers, generally don't publish the side/bank count. I'd like to see an article that helps identify whose memory is really double banked, especially at the 256MB level, since its going to take 4 modules for best performance in an 875 system. Since many of these products are best available thru the internet, I don't have the luxury of looking at the modules before I buy.

    FYI, I'm also more interested in using well matched double banked components with low timings than in overclocking to the max.

    Mushkin has very low timing memory in a 512MB configuration that is double-banked, but it seems like overkill to put 2GB of memory for $800+ into the system at this point. (I also don't know how well the system would perform with this quantity of memory as I hear that more memory can slow timings down.) Their 256MB modules are single-banked unfortunately.
    Reply
  • Anonymous User - Monday, August 18, 2003 - link

    I would personally buy the Mushkin PC3200 Level II Dual Pack located at this URL: http://www.mushkin.com/epages/Mushkin.storefront/3...

    It says that is is CAS 2-2-2 at 400MHz

    Unfortunately, Anandtech has not added Mushkin to their test products for any of these articles (not that I have seen at least) so I cannot verify the performance. I hope this due to Mushkin not supplying them samples before they complete testing and go to press. Otherwise, it is just a gross oversite by Anandtech not to include Mushkin. Whatever the case, Mushkin is a big name company with many supporters who will vouch for their quality. I am going to upgrade my memory shortly to these exact DIMMs so I feel comfortable suggesting them. 2-2-2 latency just sounds too good to pass up.

    Cheers,
    Wiley
    Reply
  • DaveH - Tuesday, August 12, 2003 - link

    What about running slower RAM in the newer chipsets? Like PC2100 in 800 FSB? Reply
  • Anonymous User - Monday, August 11, 2003 - link

    My personal SiSoft Sandra Memory Bandwidth UNBuffered test results on a Gigabyte 8KNXP (F5 BIOS) with a P4 3Ghz/800Mhz, ATI9800 Pro 256mb, SB Audigy:

    Mushkin PC3500 Level II Black
    4x512mb, 200mhz, 2-2-2-6, 2955/3017
    4x512mb, 217mhz, 2-2-2-6, 2850/2916
    2x512mb, 200mhz, 2-2-2-6, 2844/2862
    2x512mb, 217mhz, 2-3-2-6, 2423/2493

    Corsair TWINX1024-3700
    4x512mb, 200mhz, 3-4-4-8, 2724/2782
    4x512mb, 217mhz, 3-4-4-8, 2614/2723
    2x512mb, 200mhz, 3-4-3-8, 2610/2626
    2x512mb, 217mhz, 3-4-3-8, 2491/2542
    Reply
  • Anonymous User - Thursday, August 07, 2003 - link

    Need help determining SS vs DS (Single side/bank vs. Double Side/Bank) - how can you tell, as the memory mfgrs don't usually say? Reply
  • Rayalkj - Thursday, August 07, 2003 - link

    How similiar does the RAM have to be? I bought a Dell with 2x128 meg ram and want to up it to 512 megs. Do I need the exact same Brand? Just the same sizes? (ie. 2 more 128 meg sticks) Is there something I should look for especially?

    ... Yes, I am a bit of a noob at this stuff
    Reply
  • Anonymous User - Wednesday, August 06, 2003 - link

    Would this apply to nForce2 Ultra chipsets? Reply
  • Wesley Fink - Sunday, August 03, 2003 - link

    Regarding "Mixed Memory" configurations, the Best Memory Timings are the fastest timings THAT PARTICULAR COMBINATION WOULD RUN. So they are the best timings for that mix of Dimms. Mixed pairs - particularly widely different memory pairs - can take a very large performance hit in 865/875 boards. The reduction in performance is MUCH greater than we would expect.

    As was also stated, we have seen cases of 2 pairs of dimms from different manufacturers that match closely on capacity and timings that perform just as well as 2 matched pairs.
    Reply
  • Anonymous User - Sunday, August 03, 2003 - link

    Re: "Intel’s White Papers address mixed memory
    configurations only to say that they will work,
    but they will default to the slowest speed and
    SPD timings of the mixed DIMMs."

    I wish I understood this. I am pretty sure that
    I don't. For example, in the first row of the
    mixed memory benchmark table the "best memory
    timing" is given as 2-7-3-3 but the 512 MB DIMMs
    are said to run at 2-5-2-2. Could it be that this
    column should be labelled "worst memory timing"?
    And suppose that the 512 MB memory was run at the
    slower timing, 2-7-3-3, instead of 2-5-2-2.
    How does that result in a 25% performance loss?

    I would really like to understand this so that
    I could predict what will happen when I mix
    memory timings, avoid really bad DIMM
    combinations and be able to use the not so bad
    combinations. So, can someone explain what it
    really going on here?
    Reply
  • MS - Friday, August 01, 2003 - link

    I'll certainly run a few benches myself. It is really interesting that those guys who should know, that is memory and chipset manufacturers are lagging so far behind the "fanboy" community in terms of understanding how things actually work and what factors are really important.

    As far as your review goes, I am eager to see it, especially the acknowledgement (LOL)

    Michael

    Reply
  • Wesley Fink - Friday, August 01, 2003 - link

    Thanks, Michael. Your comments are appreciated, since your memory reviews are always a "must read" for everyone in the industry.

    I got an idea for an article from your review of OCZ3700 GOLD at Lost Circuits. When it posts at AnandTech, I think you will find it interesting.

    You may want to look at some of ThugsRook's game benches posted in the Forums here. As a skeptic he was trying to prove SS/DS made no difference in game benches. What he found, however, was that SS game benches were consisitently lower than DS benches. The differences were smaller than we see with SiSoft unbuffered, as expected, but they appear to be genuine.
    Reply
  • MS - Friday, August 01, 2003 - link

    Nice review, Wes.

    One single issue I have is that if you are running SiSoft unbuffered, you constantly hammer the memory, which means that the idle counter will not go in effect and you keep the maximum number of pages open at all times (I believe it is 32 combined to 16 wide pages in dual channel mode). This is really why you see the performance benefit with double-sided DIMMs.

    However, in real life applications, this benefit is not present, at least as far as I can tell. No criticism intended, just a side-note.

    Regards
    Michael

    p.s. and the guys who did some of the performance studies at Intel used to call me quite a few times .. :-)
    Reply
  • Anonymous User - Friday, August 01, 2003 - link

    This reads too much like an ad by OCZ - any non-OCZ users of the P4P800 Deluxe Asus board got a recommendation for best memory sticks to get stable, solid 1 gig of DDR333 (little, if any OC)? Thanks Reply
  • Anonymous User - Friday, August 01, 2003 - link

    In fact OCZ announced PC-3700 Gold Quad pairs at 2003-07-03 for Intel 875 chipset.:

    SUNNYVALE, CALIFORNIA
    OCZ Announces Dual Channel Gold Quad kits.

    OCZ is pleased to announce the release of OCZ PC-3700 Dual Channel Gold EL DDR memory in 1GB kits featuring quad 256mb modules based on OCZ's recently developed Hyperspeed and Extended Voltage Protection (EVP) technologies.

    OCZ HyperSpeed® technology denotes specific OCZ EL DDR ICs built and selected for their ability to run at the highest possible frequency. EVP protection allows the modules to tolerate higher voltage without compromising stability.

    "OCZ PC3700 Gold has been a dominant product," said Steve Lee, Director of Strategic Business Development. "By offering hand-tested and matched quad 256mb modules, we have the best solution for dual channel configurations on the market."

    OCZ Dual Channel Gold Quad memory will be shipping in 1GB PC-3700 Dual Channel optimized kits rated at CL 2-3-7-3 with an operating frequency of 2.75 volts. Each module is backed by OCZ's Lifetime Warranty and features a Gold layered copper heatspreader. The four matched 256MB modules are tested together on the Abit IC7-G to ensure maximum stability and performance.

    OCZ Dual Channel Gold memory has been designed specifically for use with the Intel Canterwood and Springdale chipsets, and thus offers the best performance on these platforms
    Reply
  • Wesley Fink - Wednesday, July 30, 2003 - link

    512MB Dimms are usually DS, but that will be changing with higher-density chips coming out. @56MB Dimms are normally SS right now, but there are exceptions like OCZ 3700 GOLD which are 256MB and Double Bank. The last page of the article has charts which give recommendations from best to worst performance based on memory configuration. The data is from our own testing and the Intel White Papers.

    We will include some game benches in Part 2, but ThugsRook, who regularly posts in the Anand Forums, has posted some game benches at several sites showing the performance difference in SS and DS memory modules in gaming performance.
    Reply
  • Anonymous User - Wednesday, July 30, 2003 - link

    Thanks (#25) - I too have noticed that memory vendors claims and board manufacturer compatibility charts are often at odds - seems like it's left up to the builder to actually try it and see if it runs ... (ref post #19). Reply
  • Anonymous User - Wednesday, July 30, 2003 - link

    I noticed that Asus in their P4C800 description (on their web page) says that some manufacturer's memory can only be used in certain configurations - some branda are limited to 2 sticks and some are limited in the total GB size.
    The reason they say is: "For optimum performance and overclocking stability". But if true it was rather surprising. For example, in the case of Kingston memory, Asus only two 512 sticks can be used.

    I pointed this out to Kingston and they simply responded that four sticks can be used for a total of 2 GB. The tech ignored making any comment about the Asus statement.

    So I suppose 4 sticks can be used as long as you run them at the stated settings. But I am not sure Asus means about "optimum performance".
    Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    Some real world benchmarks wure would have been nice, even if only 640x480 Quake3 numbers, just to get an idea if there really is a payoff to warrant the added cost that filling 4 banks vs 2 would entail. Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    I'd also like to see what this means in the real world. I would be interested in some gaming benchmarks, particularly UT2003.
    Thanks for the excellent article!
    Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    Hey Prometheus, please check this asap:
    http://www.overclockers.com/tips00438/
    great article btw ;)
    Reply
  • jsalpha2 - Tuesday, July 29, 2003 - link

    Pardon me, cause I'm tired. Did the article say if 4x(256) is better or worse than 2x(512). Assuming identicle brand and speed of RAM.
    I think I heard somewhere to go with just two sticks for better performance. Plus then you have open slots for later.

    Question #2 Would 2x(512) of cheaper DDR333 be better than 2x(256) of DDR400?
    thanks
    Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    Great article, it's just missing latency benchmarks. Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    Ok - pardon the newbie question, but - I'm building a P4c with Asus P4P800 board. I want 1 gig of DDR400 ram - what brand/model number do I buy - ?
    Thanks for your help.
    Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    This is all nice and good, but what does it all mean in the real world, run some benchmarks in these various modes and show us whether we should care about it :) bottom line to me is what it does for the games, if i'm losing/gaining 4 FPS i'm more likely to care about the price differences then memtest. Reply
  • Wesley Fink - Tuesday, July 29, 2003 - link

    These are quoted form Intel's White Paper, p.13 "NOTES: Ranks per Dimm (1 Rank is a single-sided DIMM, 2 Ranks is a double-sided DIMM)". The common practice of using higher-density Dimms every other Dimm on both sides (4 chips per side) is FUNCTIONALLY a Single Bank or Single-Sided Dimm.

    As for confirming that 4 dimms was faster, only the tests on the 3.0 were CPU-limited. We also determined maximum overclock on a 2.4C which was not CPU-Limited. Please check Page 7.
    Reply
  • Philippine Mango - Thursday, January 25, 2007 - link

    Wrong, you didn't use a 2.4C, you used a 2.6 processor which from what I know doesn't overclock as well as the 2.8C or 2.4C.. Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    "...we confirmed that the added memory bandwidth more than makes up for the slightly lower overclock with four double-sided DIMMs"

    To say you 'confirmed it' is quite a leap indeed... as you notably stated, you were CPU limited in going any higher for 1 and 2 sticks, whereas you clearly reached a blockade with the 4 sticks of memory. It could be that 4 sticks of memory causes a blockade in the chipset performance at some GHz, but with a better CPU you might have gone much higher with the opposing configurations.

    -Robert
    Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    "If you plan to run DDR400 as your base memory speed with an 800FSB processor, your best memory performance will clearly be with four matched double-sided DIMMs"

    Can somebody help me to understand this?

    I have only heard about 2 matched DIMMs...

    Four matched DIMMs is 2 X 2 matched DIMMS?

    Thank you very much!
    Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    While the article was interesting in that it at least confirmed Intel's white paper, I would be interested in your also testing ECC. I have a machine which does double duty as a backup server (plug the disks in the SCSI port and away it goes!). I am just curious as to the performamce hit when ECC is being used. Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    The writer does not distinguish between DS and double bank module ;) Reply
  • Anonymous User - Tuesday, July 29, 2003 - link

    Reply
  • Wesley Fink - Monday, July 28, 2003 - link

    Yes, you read it correctly. the mixed dimms can vary from very large drops - 20 to 27% or so - to very little if any drop for closely matched pairs. Performance seems to fare best when mixed pairs are the same capacities and the same "bank" configuration. Reply
  • ViRGE - Monday, July 28, 2003 - link

    Very good article, Wesley, but I'm a bit confused on your mixed vs. matched DIMM comparison. On the 1st configuration, 2x256DS + 2x512DS, the timings look to be the same as in the 1st table on page 4, the DDR 400 numbers. Am I reading this correctly? It seems odd(although believable) that memory bandwidth dropped 25%, even though it stayed as 4 DS DIMMs at the same timings. Reply
  • PrometheusN - Monday, July 28, 2003 - link

    Thanks to a reader for pointing out one correction to this article. The Intel White Paper from the 865 chart reverses 1 and 2 memory positions compared to the 875 white paper. While I did not test 865 performance in the review, I did make reference to the White Paper Chart.

    We can also wonder, with Intel not sanctioning PAT on the 865, exactly how the 865 boards WITH PAT will behave, and if memory on an 865 with PAT changes back to the same as 875.
    Reply
  • Anonymous User - Monday, July 28, 2003 - link

    You did not close your table on page eight.

    3 4 DS/td> Dual Channel

    Add a < to the "/td>" ;)

    Otherwise... Great article, very informing, thanks for taking the time to write this up.
    Reply
  • PrometheusN - Monday, July 28, 2003 - link

    Single-Sided or Double-Sided IS a functional description - but it normally is also a visual description. BEWARE dimms that skip every other chips on both sides. These have 4 chips on each side, but are functionally Single-Sided. Reply
  • PrometheusN - Monday, July 28, 2003 - link

    According to CPU-Z 1.18C, 4 Sticks of ram - single or double - do NOT disable "PAT" on the DFI 875PRO or the Asus P4C800-E. It depends on how the motherboard BIOS handles the 4 Dimms.

    Wesley Fink
    Reply
  • Shalmanese - Monday, July 28, 2003 - link

    Nice article but what are the real world consequences of these numbers? When DDR was 1st introduced, we only saw a ~10% peroformance increase from a 100% increase in memory bandwidth so I am thinking that the difference between 2 and 4 banks would be trivial. Reply
  • ghg - Monday, July 28, 2003 - link

    Hi Prom

    Nice review, as we expected from you 8-).

    Using 4 sticks of doublesided OCZ 3700 Gold disables PAT according to CPU-Z 1.18c.
    Same behavior when taking 4 sticks of singlesided OCZ 4000 ?

    Ciao

    Gary
    Reply
  • ghg - Monday, July 28, 2003 - link

    Reply
  • Anonymous User - Monday, July 28, 2003 - link

    Great article. Pity Im too late. Is single sided RAM the same as single bank (electronic) or physically the ram chips are on a single side of the stick. Mushkin in particular are wary of using the single side term. Also What about PAT acceleration in conjunction with lower latency RAM and DIMM number? Some reviews have shown lower FSB with tight timings RAM and PAT acceleration beating looser timings 1:1 higher FSB RAM systems. Ah questions questions? Reply
  • pakuens - Monday, July 28, 2003 - link

    Good article. I'm right in the middle of buying memory and it answered several questions. It saved me from an expensive mistake, as I was considering using two matched pairs, but of differing size.

    I like the unbuffered benchmark method.
    Reply

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