First publicly demonstrated in 1997 at a JEDEC memory committee meeting, Double Dynamic Rate memory was viewed more as hype than as a viable solution for personal computers. At the time, Samsung was the sole manufacturer of the memory, and even worse, the simultaneously debuted VIA M3 prototype motherboard failed after just two hours of operation – not exactly a triumphant marketing coupe of DDR technology.

There is no debate DDR memory initially had problems. However, the semiconductor industry did like one aspect of the technology: its simplicity. The DDR specification built upon the previous synchronous DRAM platform, meaning many aspects of existing fabrication processes and circuitry designs could be carried over with modest modifications. DDR die size was comparable to SDR, meaning the new memory afforded only a ten to fifteen percent premium as compared to its older sibling – a far cry from the near ridiculous prices associated with the other competing standard of the day from the now infamous RAMBUS.

Enough of a trip down memory lane. Fast forward a few years, factor in numerous fabrication improvements, note the demise of RAMBUS, and DDR ultimately became the dominate memory format for most x86 platforms. Module frequencies have scaled significantly, with the current JEDEC specification declaring an official 200MHz (400DDR) memory bus rate, though overclockers have pushed well past this boundary for the past couple of years.

Today we are examining one such overclocking-friendly memory. OCZ Technology PC-4000 Gold VX Series memory is designed specifically for high-frequency and high-voltage operation – the two most important aspects when trying to push the memory bus to its absolute breaking point. Those with Dell, Gateway, and other original equipment manufacturer systems need not apply, as this memory is marketed for the serious overclocking enthusiast.

Marketing Hype

OCZ Gold Series EL PC-4000 with Voltage eXtreme technology is a revolutionary line of memory designed to pursue a new level of DDR performance. The PC-4000 Gold VX is made to operate above the traditional memory voltage to increase speed and stability to ultimately allow the memory to thrive under high voltage. Memory performance increases with voltage, but unfortunately with many traditional modules this can significantly reduce stability and increase the potential for module damage. Unlike typical memory, VX DDR performs best at an above average voltage, and better and better as voltage is increased, all without any adverse affects to stability. Running at 3.3 volts, the PC-4000 Gold VX is capable of blistering timings of 2-2-2!

OCZ PC-4000 Gold VX is also made with OCZ’s proprietary Enhanced Latency technology to allow the modules to run at lower latencies than normally possible. In addition, each OCZ EL PC-3200 VX module is encased in a gold-mirrored copper heatspreader and is backed by OCZ’s industry leading toll-free technical support and lifetime warranty.

The Gold Voltage eXtreme product line 100% hand-tested to ensure OCZ quality and is optimized for use on Athlon 64 based motherboards. Every Dual Channel Kit from OCZ is hand tested as a matched pair across a wide variety of motherboards to ensure flawless performance on most motherboards. OCZ VX Gold Edition memory modules are rated to handle up to an incredible 3.5V without invalidating the OCZ Lifetime Warranty so that performance enthusiasts can tweak their systems without worry. Leave it to OCZ to design the ultimate high performance memory that thrives under high voltage.

Retail Box

The OCZ PC-4000 Gold VX arrived in a standard blister package containing two matching 512MB modules, which is marketed as an optimized dual-channel solution. No documentation was included, but as mentioned earlier, this memory is not being marketed to first-time computer users. If you are paying a premium for overclocking memory, then odds are you already know how to install a memory module.

Technical Analysis

The memory certainly looks impressive both on paper and in physical form. According to the specifications, OCZ has implemented numerous features to sustain low-latency operation at high frequencies. The actual latency values will vary according to voltage, officially ranging from 2-3-3-8 at 2.6v and 200MHz (400DDR), all way down to 2-2-2-8 at 3.3v and 250MHz (500DDR). Yes, you read that right: a drop in latency as frequency increases! However, note the high voltage level to reach such a low latency. Many popular motherboards do not even offer support for such high voltages.

The OCZ Gold VX series is tailored specifically to high-voltage operation, thus the moniker of "Voltage eXtreme" definitely applies here. OCZ is so confident that its Gold VX lifetime warranty extends all the way to 3.5v – good luck trying to find a similar level of warranty coverage from other mainstream manufacturers. Paired with a proprietary low-noise printed circuit board design and mirrored copper heatsink spreader, the Gold VX PC-4000 module certainly appears ready for 250MHz (500DDR) operation with little end-user effort required.

System as Tested

Overclocking Performance

Knowing very few people are going to run this memory at stock settings, the first goal was to find the absolutely highest overclock possible with our Gold VX PC-4000 modules while retaining the recommended 2-2-2-8 latency rating, despite the memory’s onboard SPD chip being preset to 2.5-4-4-10 at 250MHz. The Abit AI7 motherboard utilized for testing supplied a consistent 3.25v to the memory bus throughout all testing, which is well within tolerance of the OCZ recommendation of 3.3v for PC-4000 operation.

Once everything was configured, the bus frequency was slowly cranked up starting from 200MHz (400DDR). The system performed flawlessly at each stage, all the way to the memory’s rated speed of 250MHz (500DDR). However, the memory failed to boot above this threshold when operating in dual channel mode, even with timings relaxed to a modest 2.5-4-4-8 level.

To verify the stability of our test platform, TwinX PC-3200 XL memory from competing manufacturer Corsair was utilized, which reached a peak 265MHz (530DDR) at the same latency and voltage settings. However, just as with processors, not every memory stick from a specific model series will overclock the same. Accordingly, we tested each OCZ PC-4000 Gold VX module separately in single channel mode. One stick again reached a peak of 250MHz (500DDR), while the other stick managed a more respectable 262MHz (524DDR).

Despite the limited overclocking potential of one stick holding the test platform back, both memory models performed flawlessly at 250MHz (500DDR). Multiple hours of looping benchmarks and two weeks of daily use without a single application crash proved the reliability and stability of the OCZ Gold VX memory, which is a welcome change from memory that boots to ridiculously high frequencies only to result in exceedingly poor system stability.

Underclocking Performance

Some people may question the premise of running overclocking memory at lower frequencies, but one must take note of the expensive prices associated with low latency PC-3200 memory. The currently popular Corsair 1GB TwinX PC-3200 XL Pro dual channel kit retails at most online vendors for approximately $220 plus shipping, while the similar OCZ 1GB PC-4000 Gold VX dual channel kit retails for about $189 plus shipping at the same vendors – a significant $41 price difference.

Corsair suggests latency settings of 2-2-2-5 at 2.75v for its TwinX PC-3200 XL line, while OCZ lists 2-3-3-8 at 2.6v for its Gold VX PC-4000 when operating at 200MHz (400DDR). In an attempt to level the playing field, we tightened the latencies and increased the voltage of the OCZ review samples to match the recommended Corsair specifications. Sure enough, the Gold VX PC-4000 booted and performed flawlessly in all stability tests, which is a huge win for OCZ in regards to cost efficiency. If you are in the market for low latency PC-3200 modules, give the reasonably priced OCZ PC-4000 Gold VX series serious consideration before dropping the cash for more expensive low latency PC-3200 modules from other mainstream manufacturers.

Final Thoughts

Had our test platform’s motherboard proved capable of delivering memory bus voltage in excess of 3.25v, the tested OCZ modules would probably deliver an additional 10-15MHz with relaxed timings. This is an important consideration to make when purchasing overclocking memory, as most motherboards can not deliver over 3.2v to the memory bus. For enthusiasts in such a situation, OCZ offers a rather interesting product for increasing available memory voltage: the DDR Booster diagnostic device.

While on the topic of voltage manipulation, it should be noted that high voltage typically correlates to high temperatures. Unlike with cheap generic DDR modules, the copper heat spreader found with the OCZ Gold VX series is included for a definite reason: the memory becomes blisteringly hot at 3.3v – not just warm, but hot enough to nearly burn skin! Proper case cooling is a must, and a side fan blowing cool air from outside the case over the memory modules is strongly recommended for extended use at 3.3v and beyond.

Despite failing to deliver operation beyond PC-4000 while in dual channel mode, OCZ solidly delivered upon its stated claim of stable 250MHz operation while retaining low latency 2-2-2-8 operation. Factor in the affordable price point and superb low latency operation at PC-3200, and there is little doubt OCZ PC-4000 Gold VX memory is a great solution for the average air-cooled overclocking system.

Pros: Extremely low latency 250MHz 2-2-2-8 stable Competitive price Cons: High voltage required

Overall Rating: 8.5/10 (higher is better) Manufacturer Info: Company:   OCZ Technology Pricing:      ~$189.00 + s/h