Performance Tests

Double-Sided Memory

DDR400, 800FSB (200x4)
Intel 875 Chipset, 2-7-3-3 Memory Timings
OCZ3700 GOLD 256MB DS
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
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
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
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.

Performance Test Configuration Intel White Papers Confirm Results
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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.
  • 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
  • DaveH - Tuesday, August 12, 2003 - link

    What about running slower RAM in the newer chipsets? Like PC2100 in 800 FSB?
  • 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
  • Anonymous User - Thursday, August 7, 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?
  • Rayalkj - Thursday, August 7, 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
  • Anonymous User - Wednesday, August 6, 2003 - link

    Would this apply to nForce2 Ultra chipsets?
  • Wesley Fink - Sunday, August 3, 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.
  • Anonymous User - Sunday, August 3, 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?
  • MS - Friday, August 1, 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

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