Searching for the Memory Holy Grail: Part 1
by Wesley Fink on July 27, 2003 11:13 PM EST- Posted in
- Memory
Performance Tests
Double-Sided Memory
| DDR400, 800FSB (200x4) Intel 875 Chipset, 2-7-3-3 Memory Timings OCZ3700 GOLD 256MB DS |
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| Number of DOUBLE-Sided DIMMS | MemTest86 MB/Second |
UNBuffered Sandra 2003 Memory Test (MB/Second) |
Buffered (Standard) Sandra 2003 Memory Test |
| 1 | 1671 | 1790 INT 1837 FLT |
2974 INT 2972 FLT |
| 2 | 2544 | 2600 INT 2660 FLT |
4769 INT 4710 FLT |
| 4 | 2489 | 2861 INT 2848 FLT |
4714 INT 4693 FLT |
| DDR466, 932FSB (233x4) Intel 875 Chipset, 2-7-3-3 Memory Timings OCZ3700 GOLD 256MB DS |
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| Number of DOUBLE-Sided DIMMS | MemTest86 MB/Second |
UNBuffered Sandra 2003 Memory Test (MB/Second) |
Buffered (Standard) Sandra 2003 Memory Test |
| 1 | 1947 | 2046 INT 2145 FLT |
3447 INT 3456 FLT |
| 2 | 2964 | 3192 INT 3247 FLT |
5614 INT 5584 FLT |
| 4 | 2900 | 3421 INT 3455 FLT |
5604 INT 5609 FLT |
As you can see from the benchmarks above, SiSoft Sandra UNBuffered is a more sensitive benchmark for determining differences in memory performance than the Standard Buffered test – which can sometimes conceal differences in memory performance with buffering techniques. It also appears to be more sensitive than MemTest86 in determining memory bandwidth. This is particularly clear in the benchmarks for two and four double-sided DIMMs in Dual-Channel mode. Standard buffered benchmarks and MemTest86 show the performances of two and four double-sided Dimms as fairly equal, while UNBuffered benchmarks show that four double-sided DIMMs are about 7 to 10% higher in performance – a significant increase.
Later in the review, you will read confirmation from a respected source that the UNBuffered Memory Test results are a better reflection of what is really happening in memory performance on the 875/865 chipsets when comparing two versus four DIMMs. Therefore, for the remainder of tests, we will only use Sandra UNBuffered Memory Test and MemTest86 for benchmarking.
| DDR500, 1000FSB (250x4) Intel 875 Chipset, 2.5-7-4-4 Memory Timings OCZ3700 GOLD 256MB DS |
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| Number of DOUBLE-Sided DIMMS | MemTest86 MB/Second |
UNBuffered Sandra 2003 Memory Test |
| 1 | 1953 | 2193 INT 2203 FLT |
| 2 | 2821 | 3051 INT 3129 FLT |
| 4 | 2821 | 3318 INT 3467FLT |
Single-Sided Memory
| DDR500, 1000FSB (250x4) Intel 875 Chipset, 2.5-7-4-4 Memory Timings OCZ4000 GOLD 256MB SS |
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| Number of SINGLE-Sided DIMMS | MemTest86 MB/Second |
UNBuffered Sandra 2003 Memory Test |
| 1 | 1924 | 2076 INT 2090 FLT |
| 2 | 2551 | 2725 INT 2762 FLT |
| 4 | 2821 | 3254 INT 3194FLT |
Single-sided modules appear to perform very differently on the Intel 875/865 chipsets than double-sided modules. Both MemTest86 and Sandra UNBuffered Memory Test show that four single-sided DIMMs perform much better than two. The UNBuffered Sandra benchmark shows an improvement of almost 20% in performance when using four Dimms instead of two. This is more than double the UNBuffered Performance improvement in going from two DS DIMMs to four DS DIMMs on the 875/865 chipsets
UNBuffered Memory Performance Summary
Having established that the SiSoft Sandra UNBuffered Memory Test is a sensitive benchmark for measuring performance differences in memory configuration, it is now useful to compare UNBuffered Memory Benchmarks for one, two, and four double-sided and single-sided DIMM modules.
| UNBuffered Memory Benchmark 875/865 | ||||
| Number of DIMMS | DDR400/800FSB DOUBLE-SIDED |
DDR466/932FSB DOUBLE-SIDED |
DDR500/1000FSB DOUBLE-SIDED |
DDR500/1000FSB SINGLE-SIDED |
| 1 | 1790 INT 1837 FLT |
2046 INT 2145 FLT |
2193 INT 2203 FLT |
2076 INT 2090 FLT |
| 2 | 2600 INT 2660 FLT |
3192 INT 3247 FLT |
3051 INT 3129 FLT |
2725 INT 2762 FLT |
| 4 | 2861 INT 2848 FLT |
3421 INT 3455 FLT |
3318 INT 3467FLT |
3254 INT 3194FLT |
In all cases, on both 865 and 875 chipsets, with both single-sided and double-sided DIMMs, four DIMMs is the best performing memory configuration at DDR400(1:1) or higher speed. This may come as a surprise to many of you looking for memory for your 865/875 motherboard. As expected, two DIMMs in dual-channel memory configuration performed better than a single DIMM in all cases. Beyond this, we see that two double-sided DIMMs perform much better than two single-sided DIMMs, but that four single-sided DIMMs perform almost as well as four double-sided DIMMs.
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42 Comments
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Wesley Fink - Friday, August 1, 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.
MS - Friday, August 1, 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 .. :-)
Anonymous User - Friday, August 1, 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)? ThanksAnonymous User - Friday, August 1, 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
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.
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).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".
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.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!
Anonymous User - Tuesday, July 29, 2003 - link
Hey Prometheus, please check this asap:http://www.overclockers.com/tips00438/
great article btw ;)