Comparing Memory Bandwidth: UNBuffered Memory Performance

In our article, 'Searching for the Memory Holy Grail — Part 1', we demonstrated that the UNBuffered SiSoft Sandra Memory Test correlated very well with MemTest86 bandwidth results. With all of the Buffering techniques disabled, scores are much lower — sometimes a 50% drop — than the scores you are accustomed to seeing for Sandra Memory tests. However, the unbuffered scores have proven to be a very sensitive measure of memory bandwidth. Regarding memory performance, we will be looking at the maximum stable overclock for the memory and the SiSoft Sandra UNBuffered Memory Test.

The idea of the UNBuffered Memory Benchmark is very simple — you merely turn off all memory buffering techniques. Sandra makes this very easy to do. Select 'Memory Benchmark', right-click 'Module Options', and uncheck the nine boxes that are related to buffering.




Please keep in mind that the Crucial DDR333 modules using Samsung memory are single-sided DIMMs. As we illustrated in 'Searching for the Memory Holy Grail — Part 1', the performance of two SS modules is lower than the performance of two DS modules in 875/865 boards, and cannot be directly compared.

All memory tests were run on an Abit IC7, Intel 875 Canterwood motherboard with BIOS revision 1.5, and a 2.4C Pentium 4, 800FSB processor that has reached 290MHz (1160FSB) on this motherboard.


Crucial DDR333 Samsung SS Performance
Intel 875 Chipset, Dual-Channel, Maximum Overclock
DDR Memory Speed Memory Timings Memory Voltage
(vDIMM)
UNBuffered
Sandra 2003 Memory Test
(MB/Second)
450 Maximum SPD
2.5-7-4-4
2.7V 2472 INT
2460 FLT
460 3-8-4-4 2.8V 2436 INT
2527 FLT


Given the ability of this Samsung memory, rated at DDR333 or DDR400, to reach DDR460 at 2.8V, we can fully understand why OCZ chose this as their base memory chip. However, as good as this performance is, it does not match the specified performance of OCZ 3700 GOLD of DDR466, 2.5-7-3-3, at 2.65V. So how does a manufacturer of high-speed memory get from this base performance to the performance of 3700 GOLD?

Lasering for Heat Dissipation

When information about OCZ using Samsung TCB3 chips for 3700 GOLD first appeared, others were asking the same question we were asking: how did OCZ get a memory rated at DDR333/400 to the performance levels of 3700 GOLD — or did they?

All memory manufacturers (as well as CPU and chipset manufacturers) "bin" chips. This means that they sort chips by speed capabilities. The top-performing chips are then used in the highest-speed products — the rest going into lower rated products. OCZ explained that, in addition to speed binning, they laser the chips to improve heat dissipation before sorting, using the best chips for OCZ 3700 GOLD. They also released an internal document describing the lasering process and how it improves heat dissipation. The information below is from the released internal document:

"INTERNAL USE ONLY : ENGINEERING DEPT -TW-CA

Thermal modification of standard DDR DRAM TSOP packages , for increased thermal dissipation and speed reclassification.

Note #1 : Reference EL DDR packing specification is linked at /spec/elddr.html

Purpose : Increase speed of ( SEC packaged ) TSOP , through using EL DDR packaging theory. To fill product shortage during die revision change

EL DDR Packaging : by decreasing the thickness of encapsulate (low thermal transfer rate ) we are able to effectively increase heat dissipation in DRAM and thereby increase the effective speed of each IC . Using a third party fabrication and packaging plant this theory has been proven and the (B) die revision OCZ EL DDR die had great success. Average maximum speed increase during stage 2 testing has been verified over 23 MHz.

Proposition: While dies fabricated by 3rd parties for OCZ in 3rd party packaging have proven successful to this point . We feel that to insure our success we should supplement by speed binning large quantities of 3rd party IC's and by physically modifying the package decreased thermal resistance and re-speed grade the ICs using the standard Advantest ATE.

Industry Disclosure: See Ryan Petersen

Process Engineering : See XXXXXXXXX

Process Overview :

Samsung semi will provide die location information , we will be using the DP-7 CO 2 laser to remove the surface material from the package face only average laser cut depth is 7mill . After surface removal the package should be sent to ISE for environmental test and then re-speed graded after speed grade and classification chips will be marked ( standard process) and standard process thereafter."


A Closer Look Testing the Process
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  • Anonymous User - Tuesday, August 12, 2003 - link

    For that.. Ask Corsair how All Components is doing the job for them? LOL LOL
  • Anonymous User - Tuesday, August 12, 2003 - link

    OK- Great hope they are turning their business around. Ask them to why does some of the modules have the Delta Omega logo?? Is PDP still building for them????????
  • Anonymous User - Tuesday, August 12, 2003 - link

    OK- Great hope they are turning their business around. Ask them to why does some of the modules have the Delta Omega logo?? Is PDP still building for them????????
  • Anonymous User - Tuesday, August 12, 2003 - link

    With stupid people like #54, who needs marketing?
  • Anonymous User - Tuesday, August 12, 2003 - link

    Everyone is better than the OCZ every knowledgeable person has come to know and despise.

    The question is, if, as is claimed, they have repented, why even keep the old, blackened name? There's no good reason.
  • Anonymous User - Sunday, August 10, 2003 - link

    Going back to when corsair were first marketing XMS2700 in the UK they sent review sites and stores based in the UK modules based on Samsung CTL CB3 IC's.As you may know these IC's were truely awesome and all the reviews showed the ram hitting ddr400+ with tight timings.One large UK based store even pealed off the heatspreaders on their forum and showed the modules in all their glory...we were all bought and imediately ordered.

    Well the modules started arriving and nothing worked as well as the review samples Corsair had sent out...So we all removed the heatspreaders off out modules only to find Micron PC2100 under them.All posts made on one particular forum about this were edited out at corsairs request, the review was heaviliy edited and RMA's were refused as we had removed the heatspreaders.

    Don't tell me Corsair are any better than OCZ because they are not...I don't see any Corsair basing here though.

    OCZ are working hard on what matters to customers today...Good ram and an excellent after sales service.If you have a problem im sure an email will get them helping you...
  • Anonymous User - Sunday, August 10, 2003 - link

    Yeah, god forbid a company attempt to create a good product. You people going to tell me that Corsair hasn't done shady things to sell products? You've got to be kidding. I wouldn't be surprised if at least one of the people slamming OCZ here work for Corsair or some other company. OCZ are putting out some killer memory right now, who cares what they've done in the past? Or what they'll do in the future? And since when has our quest for the best performance ever been about the company? Gimme the good stuff, I could care less who's making it. You fanboys need to get a grip.
  • Anonymous User - Sunday, August 10, 2003 - link

    I work at ocz , for those of you calling OCZ a fraud , or bashing OCZ can you do us all the great favor of posting under your real name , instead of as anonomous

    If you had some genuine problem with ocz email me
    oczguy@ocztechnology.com , we certainly did not always have the great service we do today and if you had a problem I would personaly be glad to help you . Also it seems many people confuse us with other companies.

    If you have not had a problem , or are not willing to resolve it ,please stop spewing garbage anonomously. Otherwise I cant help but think that your simply an employee of our competition spreading rumour for your own gain.

    I challenge anyone with a real past problem to email me , so that I can at least have the opportunity to solve it. If you have not had a problem please refrain from the trash talk.

    I am not saying here that people did not in the past have service problems with ocz , to be clear , I am however saying that the level of trash talk in the comments sections is out of control. Anyone who has in the past had a problem can contact us to have the issue resolved.

    Enough said



    thanks for listening to my rant -OCZGUY
  • Wesley Fink - Sunday, August 10, 2003 - link

    The advantage of being a very large site like AnandTech is that ALL of the memory makers advertise here. I will not justify the last comment with a defense, but if you look around you will see how ridiculous these comments really are.

    I came from a site that had no advertising while I was there, and from the first time we talked Anand has encouraged my independence. Why is it that when we report information that is different from what you might believe, it is proof we have sold out? The real sell-out here is some of the narrow-minded self-serving and totally false comments that have been posted as commentary.

    It is truly amazing what some people will say when they can hide behind 'Anonymous'.
  • Anonymous User - Sunday, August 10, 2003 - link

    Hehehe, OCZ is nothing more then a marketing firm. The so called plant is a "memory plant" that OCZ went into business with. The so called "memory plant" is where they bought their memory 2 years ago. They needed to move out of Indiana because of the amount of fraud that was being reported.

    If half of you did your research about this company you would realize. Want to know the true info? Ask Martin Krohn. He witnessed the true nature of the company.

    You see OCZ on Anandtech it's not because of their products it's because they paid Anandtech for advertising. Do you really think Anandtech would "turn down" paying clients? This is a business now folks. I can guarantee you that no bad reviews of any of the paying advertising clients are on this site. Anandtech is a total sell out. Just look at their GeForce FX 5900 review! That has never been fixed yet either! This site is horrible now. It ranks up their with Toms and now [H] big business sites suck.

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