OCZ 3700 GOLD: Building High-Performance Memory
by Wesley Fink on August 7, 2003 8:34 PM EST- Posted in
- Memory
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."
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Anonymous User - Saturday, August 9, 2003 - link
Which board did you use #17? Early 865PE and 875P boards had BIOS issues with lots of memory modules (Corsair, Kingston, etc.), not just OCZ.Anonymous User - Saturday, August 9, 2003 - link
Companies get turned around all of the time - for better or for worse.If I had read this before my June upgrade, things may have gone differently.
In my case, I got OCZ for the first time (2 x 256 3200) for my 865PE board. Despite Anandtech's report on compatibility, I have to run in "slow" timing mode to make sure my system won't crash. Never have I had such poor performance in memory. The full featured board (I skipped a few options) and the 875 version cost about the same as good memory replacements. Oh well...
Anonymous User - Friday, August 8, 2003 - link
Apparently the 'lasering' process is performed after binning, so why were unbinned DIMMs used? Unless the sample size was significant (I would not be confident with under 30 DIMMs of each type, personally) it would make a lot more sense to have the modules binned before modification so that at least some baseline is established. Without this then all you have is a statistical correlation (by the way, what was the nature of this beyond it being positive?) hence the higher number of modules required. That is not to say of course that even if they are binned then you can get away with a very small population, but at least reduce it to perhaps 10 to 15 of each type.I would be very interested to learn what n and r were in each case. Also, what statistical method was used to determine correlation? Spearman's rank method? Was this tested at 10%? 5%? 1%?
On a different note, I've become aware that some of OCZ's banner adverts suffer unfortunate spelling and punctuation errors...
Anonymous User - Friday, August 8, 2003 - link
I've read alot of things about OCZ a lot of them bad....but that was probably a year or two back. I've also read the reviews for this ram on Hexus and they seem to reach similar conclusions as the article here. It makes me wonder is everyone just shilling for this product or has OCZ turned their image around and are they now producing good cutting edge products....being in the market for some ram for my IS7 I'm really tempeted to try these.Anonymous User - Friday, August 8, 2003 - link
Of course there's no word about OCZ's shady practices. OCZ bought favor over on ABX, and now they've infested AT with their garbage. Hell, why not just print an OCZ press release instead of an article?Watching what's happening to AT is like watching Tom's HW after Tom decided he was too important to write. When you pass off all of your work onto unqualified lackeys, articles like this and the power supply one are the result.
Anonymous User - Friday, August 8, 2003 - link
Can someone please explain memory timings to me?What's the differance from 2-7-3-3 to 3-8-4-4? Is it more than the amount of data written per CPU cycle? Or does it have nothing to do with that?
Thank-you!
Anonymous User - Friday, August 8, 2003 - link
Im not a huge OCZ fan, but it does piss me off that so many people continue to believe that they are this fraudulent enterprise that doesnt exist. I suppose you think Mushkin doesnt buy reviews? Maybe you have the notion that Kingston doesnt relable memory? Ive seen Corsair shut sites down for comments they didnt agree with.Anonymous User - Friday, August 8, 2003 - link
Kishkumen,Everyone at one point or another has a bad piece of hardware, it happens. You just need to RMA it. You think no one else has RMAs? LOL check out Corsair's forums and their RMA rate, then get back to me.
Kishkumen - Friday, August 8, 2003 - link
OCZ makes me extremely nervous. I've had 2X256MB of PC-2700 stuff from them that has never worked at 333MHz from day one on both modules. So I relegated them to a KT266A motherboard running 266MHz with crappy timeing and wrote them off as a bad decision. Well, all of a sudden this Gold stuff suddenly appears and since I've recently upgraded to a Barton core and don't have memory that with work at 333MHz, I ask myself why I'm living with memory that is bordering on fraud so I decide to give tech support a ring and was surprised to find them somewhat helpful. I'm sending back the modules and if they send me back two modules that actually work as advertised, perhaps they'll warrant a second chance. In the meantime, however, I'm going to stay the hell away from OCZ. There are no shortcuts in this business and it seems OCZ has tried them all and failed 90% of the time while pawning off those failures to their customers.Radelon - Friday, August 8, 2003 - link
Great article, for me personally this article is showing the average experience that people will receive from their OCZ 3700 or higher ram. I have 2x256 OCZ PC3700 Gold that will reach DDR540 @ 2-6-3-3 timings. I have 2x256 OCZ PC3700 Premier that will reach DDR530 @ 2.5-6-3-3. That's way beyond spec and I'm very pleased with them. You just can't go wrong using OCZ these days.For comparison, I have 2x256 Corsair 3700xms that will only do DDR490 3-8-4-4, and they aren't 100% stable there. From personal experience I will never buy Corsair again, not when I can get OCZ which will run way over spec.
Again great article, it seems things are always gettin' better for OCZ.