OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition 2GB Kit Page: 1

OCZ Technology
first entered the memory market in August 2000, and their vision was built around the determination to manufacture the best high speed DDR and RDRAM available. OCZ was founded by enthusiasts, for enthusiasts, and their commitment to the end-user was paramount in achieving their goal.

Seven years on, OCZ Technology has become the innovator and not the immitator in many areas, particularly with their recent branching out into mainstream enthusiast hardware. But anyway, I'll let OCZ tell you what it does best:

We at OCZ diligently work to improve communication with CPU and motherboard chipset manufacturers prior to the release of their products. Only in this manner can we fine-tune our memory's SPD settings, ensuring a synergistic relationship between the memory module, memory controller, and microprocessor. In today’s rapidly evolving semiconductor industry, such communication is not simply research, but a necessary component of our manufacturing process.

At OCZ Technology, one of their main aims is to ensure customer satisfaction:

At OCZ we have one primary goal, and it is to make sure that every customer is 110% satisfied. Every employee at OCZ is dedicated to accomplishing this goal. Our engineers are constantly developing the fastest and best performing products. Our finance department works every angle to bring customers our product at the best price. Our marketing department ensures all the information needed to make an informed purchase is available and presented in an easy to understand format. The technical support department constantly studies and tests the latest hardware to be as informed as possible to help you with any issue you may have. Our customer service department is filled with customer satisfaction fanatics who will refuse to let you be unsatisfied.

Today, I have been fortunate enough to have been asked to review OCZ's DDR2 PC2-6400 CL 3 FlexXLC Edition RAM . So without further delay, let's get acquainted with our review subject.

OCZ DDR2 PC2-6400 FlexXLc

Most current memory manufacturers appear to prefer packaging their modules in clear plastic blister packs. OCZ's packaging format is no different. Although the clear blister pack clearly shows off the new modules virgin appearance very nicely, I do have some doubt in its integrity if subjected to heavy handling in the post. However, I must say though to OCZ's credit; these review modules made it safely from the otherside of the planet to Australia in perfect condition.

I have decided to be very brief with the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition packaging as it has been covered in previous reviews here at Overclock3D. Feel free to check out James Napiers take on it here.

OCZ FlexXLC front [ackaging

OCZ rear packaging

Ok enough of the packaging. Let's have a closer look at these badboys, including their specifications.

OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition 2GB Kit Page: 2

The following information has been taken directly from OCZ Technology's website:

 800 Mhz DDR2
EPP 3-4-4-15
 Available in 2GB (2x1024MB) Dual Channel Kits
 OCZ Lifetime Warranty
 2.1 Volts (2.4 Volts)*
 240 Pin DIMM
 2 x 1/4" ID (inner diameter) barbs

Special Features
 FlexXLC Heatsink**
 2.35V EVP***

Part Numbers

2GB (2x1024) D/C Kit PN - OCZ2FX800C32GK


A Closer Look

In this day and age it's great to see manufacturers like OCZ optimising their RAM for particular chipsets, and the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition sticks are no different. This 2Gb kit is in fact optimised for NVIDIA® nForce® SLI™ platforms. The way that OCZ achieved this was through their new EPP-Ready (Enhanced Performance Profiles) memory modules. Essentially, the module actually has two programmed speeds; one when run on an NVIDIA® nForce® SLI™ based motherboard (nforce 680i) and another for other boards based on competing chipsets.

This latest edition to the highly-awarded OCZ Flex XLC product family is engineered to produce significant performance gains on the latest NVIDIA® nForce® SLI™ platforms by implementing Enhanced Performance Profiles (EPP) and allowing the memory to operate at a stable 800MHz at CL3 upon start up. The PC2-6400 CL 3 Flex modules are integrated with an EPP programmed SPD to immediately boot at the correct settings to produce 3-4-4 timings on nForce 680i motherboards.

Like their faster siblings, the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules feature E.V.P (Extended Voltage Protection) allowing you to run the RAM at 2.35v without voiding your warranty.

OCZ FlexXLC front

OCZ FlexXLC alternative image

The OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules utilise OCZ's patented XLC (Xtreme Liquid Convention) heatspreader. The XLC heatsink according to OCZ delivers superior heat dissipation via a hybrid copper and aluminm design alterable between passive air or water cooling. It's nice to see OCZ incorporating the benefits of running water-cooling into their high-end RAM modules.

I'm sure that you'll all agree that the XLC heatsinks look extremely eye-catching and would look fitting in any high-end rig. I must also say that the weight of these modules is nothing short of 'hefty' to say the least, and they ooze quality. I have included an image below as a comparison to the OCZ OCZ PC2-6400 Titanium 2Gb DC Kit review that I did a few months ago, just so you can see the size difference between the two.

OCZ FLexXLC and Titanium comparison

I was unable to remove the heatsink from the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules to give you a glimpse of the IC's on the PCB beneath, but I did try.

Now that we've gotten closer acquainted with our review subject, let's see how well they perform.

OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition 2GB Kit Page: 3
Test Setup

Intel Core2Duo E6850 "Conroe"
Asus P5B Deluxe wifi/ app (Configure DRAM timing by SPD turned off)
Graphics Card:
ASUS EN8800 GTS 640Mb
Hard Disks:
2x Seagate Barracuda 250GB SATA-II 7200.10 (RAID0)
Power Supply:
Silverstone ST60F 600W PSU
Operating System:
Windows XP SP2

In order to give some sort of comparitive analysis of how the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules perform, I will be using the results from my previous OCZ PC2-6400 Titanium 2Gb DC Kit review. However, as I now no longer own an E6600 processor I will be down-clocking my current E6850 processor to 2.4Ghz (266 x 9) for the duration of the review.

Prior to beginning this review I made an effort to see what kind of performance the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules were producing via the net. Now, I have seen reports of this RAM exceeding 550Mhz and even above that, but what we are aiming for here is stability. Sure I was able to push this RAM to over 550Mhz but things certainly weren't stable at that level. In fact, you may see numbers here that may be lower than other reviews, but you can be certain that these are rock solid stable....instead of the 'push the RAM as fast as it can go without regard for stability' mentality. It's simply not enough to get the machine to boot, fire up CPU-Z and grab a screenshot for street cred because the machine ends up being unusable - impressive, but ultimately quite futile.

For me personally, stable means four completed tests using the Stress Prime 2004 Orthos Edition (sp2004.fre3.com/beta/beta2.htm) 'blend' test, to strain both memory and CPU simultaneously. For the review overclocking process I tried to keep the RAM at a 1:1 ratio and the voltages at a stock level for as long as possible, but ulimately an 'anything goes' policy was adopted to see how far the RAM could be pushed without sacrificing stability.

The first test involved ensuring that the memory could run stable at stock speeds. This may seem a bit of a strange test, but unfortunately some modules we've tested here at OC3D in the past have fallen over at this first hurdle. The OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules are designed to run at 3-4-4-15 timings on NVIDIA® nForce® SLI™ platforms using Enhanced Performance Profiles (EPP).

I'm pleased to say that the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules passed the test with flying colours, managing to run at 3-4-4-15 / DDR2-800 with 2.35v on our Asus P5B Deluxe test bed. I would have liked to have run these modules at (1T) but unfortunately the P5B Deluxe's bios doesn't allow setting the Command Rate to either 1 or 2T. I have included '2T' benchmarks in this review, but bear in mind that at 3-4-4-15 (1T), the performance would typically be better by around 3-5% in most cases.

Lowest Latency 3-4-4-15 (2T) Timings @ Stock Speed (400Mhz / 2.35v)

3-4-4-15 cpu screenshot

3-4-4-14 memory screenshot

It is well known that gamers prefer to run their memory at low latencies (rather than high frequencies) as this is an easily tweakable setting and provides decent benefits in most games. After a little tweaking the modules managed impressive timings of 3-4-4-15. Not a bad result for modules designed to run at a little more relaxed timings on a non-EPP based motherboard.

4-4-4-15 (2T) Timings @ Stock Speed (400Mhz / 2.1v)

OCZ FlexXLC 4-5-5-15

Memory 4-4-4-15

5-4-4-15 Timings @ Stock Speed (400Mhz / 2.1v)

5-4-4-15 CPU

Memory 5-4-4-15

5-6-6-15 Timings @ Highest Frequency (547.5Mhz / 2.35v)

CPU 5-6-6-15

Memory 5-6-6-15

I must admit at being a little surprised at the highest attainable frequency of the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules. I felt sure that they would allow quite sufficient overclocking headroom with looser timings, but alas, no amount of pushing would get them stable at higher frequencies.

For the benchmark phase of our review, OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules were subjected to popular benchmarks at OC3D in order to illustrate outright performance. All benchmarks were run three times and an average taken to guarantee uniformity of the results. Now let's head over to the next page to see how the modules performed in the benchmarks.

OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition 2GB Kit Page: 4

From the graphs below we can see that the Intel Core2Duo processor and P5B Deluxe chipset combination does not suffer from any kind of memory speed bottleneck and the larger speed increases can only be obtained by increasing the CPU speed.

Everest Read Score

Everest Write Score

Everest Latency Score

SiSoft Sandra further reinforced Everest's results, by illustrating the potential bandwidth and low latency at DDR2-547.5 speed.

SiSoft SANDRA Bandwidth

SiSoft SANDRA Latency

The Super-Pi benchmark produced an anomaly in the results where my down-clocked E6850 performed almost a second slower than my original E6600. The reason behind this is more than likely down to the fact that the E6850 is designed to be run on the faster 1333 bus.

Super-Pi benchmark

The CS:S Stress Test certainly illustrated the benefits that the increased bandwidth provided by the OCZ PC2-6400 FlexXLC modules, consistently beating the budget PC2-6400 Titanium modules at stock frequencies. However, it was still beaten by the OCZ PC2-6400 Titanium's highest frequency by around 7 fps.

Counter Strike: Source Score

Once again 3DMARK 06 illustrates the added performance benefits of the OCZ PC2-6400 FlexXLC modules with tighter timings at default speed. And yet again with our processor overclocked the FlexXLC modules ramped it up again and produced a better end result.


Let's head over to the conclusion page to see just how well the OCZ PC2-6400 Titanium 2Gb Kit performed in our review.

OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition 2GB Kit Page: 5

As far as I'm concerned the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules are undoubtedly the sexiest looking RAM currently available. They look sharp, agressive and extremely formidable. During our testing the modules felt warm to the touch, but never progressed to anything worse than that. Which is testament to the cooling efficiency of the XLC heatsinks themselves. Further, OCZ in their wisdom have enabled those with water-cooling setups to be able to integrate cooling of their performance RAM with relative ease.

To be honest I was expecting slightly bigger things form the modules as far as overclocking was concerned, but given that overclocking can be a hit and miss affair dependent upon quite a number of variables and the uncertainty of component mass production. However, all things considered the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules are certainly no slouch when it comes down to performance. With the ability to be able to run tight timings of 3-4-4-15 at stock timings on a non-EPP based motherboard, OCZ are certainly onto a good thing.

Sure the FlexXLC's chips aren't highly sought after Micron D9, but the 'unknown' IC's certainly give a very respectable account for themselves. Further, the highest frequency that we were able to obtain with the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules still provided consistently higher results in all benchmarks over the OCZ PC2-6400 Titanium modules.

To be honest, I feel that the OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules would lend themselves well to the gaming end of the spectrum. The modules feel very 'punchy' and responsive even at stock speed. After a little bit of tweaking and further testing the sweet spot for these modules appears to fall around the DDR2-450 range at 3-4-4-15 timings. But all things considered they are certainly a worthwhile investment for those prepared to outlay the cash.

Additionally, kudos to OCZ for providing the ability to run this ram up to 2.35v without voiding the warranty.

The OCZ DDR2 PC2-6400 CL 3 FlexXLC Edition modules are available from Komplett for £65, and this isn't really that much extra to fork-out over the budget orientated OCZ 2Gb DDR2 PC2-6400 Titatium XTC modules that we compared it against.


+ Lifetime warranty and EVP up to 2.35v. (non-EPP) and 2.4v on EPP based motherboards.
+ Tight timings right out of the box, even on a non-EPP motherboard for which they were designed.
+ Cooling performance further enhanced by its ability to be included in a water-cooled setup.
+ Appearance.
+ Respectable price
+ Quality

In order to water-cool you will need to include smaller fittings into your loop.

Recommended Award Gamers Choice Award

Special thanks to OCZ for supplying the review sample

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