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Review: Memory Shootout - Extremely High Performance DDR using Samsung TCCD DRAMs on Socket 939 AMD64

by Ryszard Sommefeldt on 14 March 2005, 00:00

Tags: Samsung (005935.KS)

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Introduction

Samsung TCCD
Click for a larger version

The demise of Winbond's BH-5 memory modules saddened many an enthusiast. The DRAM device of choice for those looking to push their system to the limits, it cropped up on many a memory manufacturer's high performance DDR memory modules. Rated to 2-2-2 with low Tras of 5 or 6 at DDR400 with enough voltage, the DRAMs also get an entirely new lease of life when you considerably over-volt them. Well, overvolt in terms of the JEDEC standard voltages for DDR DRAM devices, but when you're simply giving the DRAM what it really craves, to run at JEDEC voltages with BH-5 would be rude.

You can argue that OCZ developed their DDR Booster, a device that can supply a feedback voltage to the memory circuit and run modules on the mainboard much higher than the mainboard can hope to provide on its own, just for the BH-5 DRAM. Overclocking enthusiasts (hello guys!) pioneered the supply of DRAMs with voltages in the 3.2V+ range, weeding out the devices that loved it more than standard JEDEC supply, and after years of having to voltage mod your mainboard for extra supply, OCZ's device lets you do so in relative safety without violating any warranty.

So you can see why modules like Corsair's original XMS3500 and Mushkin's utterly awesome Level2 PC3200 are so sought after, the PCB and BH-5 combination crying out for 3.5V and the ability to run at 250MHz or so while retaining 2-2-2 timings with low Tras, and even higher if you want to back off on the timings slightly.

Without any BH-5 production (despite the odd rumour that someone might license the IC design and start making it again in small quantities) these days, what's an enthusiast on the lookout for versatile memory modules to do? In recent months, the answer has become fairly obvious, Samsung's TCCD DRAM IC cementing itself into the minds of overclockers looking for a DRAM that'll do low-latency DDR400, but also DDR500 with ease at good timings, and more.

A DDR500 (250MHz) IC, it was quickly found that it was happy doing 2-2-2-5 at low-ish voltage at DDR400, making it the perfect foil for the user looking for a large chunk of overclocking performance while maintaining the DDR400 performance that their system enjoys the majority of the time. There are some exceptions to the rule: some TCCD memory sticks, dependant on PCB, aren't happy at 2-2-2 with DDR400 and only like running around DDR500.

Finally, TCCD isn't anywhere near as happy running memory voltages in the 3.0V+ range, like BH-5 is. In the ranges it does enjoy, it's not so happy doing 2-2-2 at high speed, which makes it ultimately less appealing to the hardcore overclocker than BH-5, but it has no issue running very high memory clock at more relaxed timings, something that BH-5 sometimes has a hard time doing.

It's all dependant on the ICs, the PCBs they're mounted to and the amount and quality of voltage you can give them. Poor voltage supply in terms of being 'clean' with low ripple is as key to running high speed with DDR memory as the amount of voltage you can supply. You can find better results at lower Vdimm sometimes, simply because your PSU and mainboard aren't keeping a higher Vdimm signal within acceptable limits.

So while we mourn the death of BH-5, we welcome the birth of Samsung's TCCD DRAM IC as just the thing to fill the gap, if hunting down some original XMS3500 or similar isn't your thing.

We rarely review memory modules at HEXUS and since it's now my job to do, I'm keen to do it properly. Today's article rounds up three dual-channel 1GB memory kits, based on Samsung TCCD, and puts them through their paces using a test suite I'm still evolving to fit how I think memory should be evaluated. So bear with me as I ramp up our memory-based content at HEXUS using a set of systems I'm creating to help us do it properly.

To ease myself into it gently, I'm sticking to performance on Socket 939 AMD64 for this article, before branching out with Socket 754, two Intel systems and possibly some older Socket A hardware that'll let me give you the bigger picture.