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 - Sunday, August 10, 2003 - link

    Spme of You people Deserve to get ripped off by This kind of BS Marketing
    & Fake memory "Companies" who do nothing
    but marketing.

    This Thing exists FOR the US market lol.
    No other market would ever buy any of it.
  • Anonymous User - Sunday, August 10, 2003 - link

    What a ridiculous post by #45. Are you really that narrow? This isn't some criminal court case, we're talking about how memory performs and if it's worth your while. Sure, OCZ's past is suspect, but all of that happened two YEARS ago. It's well known that OCZ has been overhauled since then. The fact that HUNDREDS of OCZ users that have posting on Internet message boards have raved about how great OCZ's latest modules have been and how quick and pleasant their tech support and customer service are should be all the proof you need about anything related to OCZ products and OCZ support.

    Who the hell cares about binning, lasering, splitting, or how any of that crap is done. OCZ memory modules work and have worked well for many many months now. That's the fundamental point of this article. If you can't understand that then you just don't know how companies in this industry work, and that's, well, sad.
  • Anonymous User - Sunday, August 10, 2003 - link

    #45 If someone here has a bad ocz product ,or even in the past had one, they can contact ocz to get it taken care of , oczguy@ocztechnology.com and oczguy2@ocztechnology.com they I am sure will be very helpfull

  • Anonymous User - Sunday, August 10, 2003 - link

    If AnandTech wants to make this more believable, they should ask OCZ for an invitation to their "factory" where they bin and send chips to their "third party" lasering people, and where they reassemble things on their PCBs. Find out where they get the PCBs, and have them show you the process of assembly. Ask to see the deed to the building, and verify who the owner is.

    Then find out similar things about these lasering people.

    This is the several dozenth incarnation of OCZ, and their history is all too criminal to ignore. Why are they not standing behind their old products with which they defrauded so many people?

    If you want to earn a good name, you earn it by doing the right thing.

    Fool me once, shame on you. Fool me twice, shame on me.
  • Anonymous User - Sunday, August 10, 2003 - link

    Hey, I hear Communist China has revolutionized the "raising the dead" technology they've been working on so long. I think I'll see if they can raise the grandparents I never met for me. It's only a few hundred thousand dollars each corpse! Just because the same government murdered over 100 million people in the last 54 years doesn't mean anything! This must be true! I want it to be true!
  • Kishkumen - Saturday, August 9, 2003 - link

    #11 Apparently you read my post, but don't understand simple senteces very well. Maybe if you read it slower next time you'll realize that when I say "I'm sending it back" I probably mean to say "I'm sending it back". You must have the comprehension of a two year old.
  • Anonymous User - Saturday, August 9, 2003 - link

    OCZ gold is returnable , if you bought the wrong products on accident or have any trouble you should email them , oczguy@ocztechnology.com or oczguy2@ocztechnology.com are always helpfull, really nice folks

  • Anonymous User - Saturday, August 9, 2003 - link

    hi all,
    Just a tip for all those like myself who bought an Msi 865PE motherboard. I wanted to get the pc 3700 gold ocz, but ocz reps emailed and told me MSI motherboards don't work well in async mode (>400MHz ram). Please remember to email your ram manufacturer before purchasing because ocz gold is not returnable. Hopefully, MSI will make another BIOS release to work well in async.
  • Anonymous User - Saturday, August 9, 2003 - link

    I heard OCZ had a pact with satan , how else could they make the memory run so fast. :-D
  • Anonymous User - Saturday, August 9, 2003 - link

    Think I will be picking up a pair of these, I have been a fan of OCZ memory for some time,

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