Some time ago now I wrote an Intel Core i7 memory performance guide that looked at the various performance impacts certain memory configurations had on the Core i7 platform. One of the conclusions that I came to, based on the testing, was that in terms of value, users are going to be better off with lower clocked lower latency memory, rather than the high-speed 1600MHz and 2000MHz kits that are now getting around. Here is a quote from that conclusion…

“Currently a 6GB DDR3-1600 (8-8-8-21) memory kit is going to set you back at least $250, whereas a DDR3-1066 (7-7-7-20) kit can be had for ~$150. Given the small performance difference between these two, we feel you would be mad to pick up the more expensive option. That said, most users will just be fine running a 3GB triple-channel kit, which can be had for less than $100. This could be good news for those "budget" Core i7 920 builds.”

Since writing that article some 7 months ago now a lot has changed, and while the message remains very much the same, DDR3 pricing has changed dramatically. Whereas late last year 6GB DDR3-1600 kits were fetching over $250 US, they can now be had for less than $100 US, which is really quite amazing. That said, at this price do not expect anything amazing, with almost all kits designed to work at 9-9-9-24.

However OCZ has come up with one of the cheapest and most impressive CAS7 kits designed to work at 1600MHz. The OCZ DDR3 PC3-12800 Reaper HPC memory kit, which comes in 6GB capacities, can be picked up for just $140 US. This is less than the price of DDR3-1066 just 7 months ago, and with timings to match lower clocked 1066/1333MHz memory, these new Reaper HPC memory modules are pretty special.

This memory kit is only available in 6GB capacities, at least for now, which means the user gets three 2GB modules. They are covered by the OCZ lifetime warranty, which will see them operate at 1.65v, which is the maximum safe voltage for the Intel memory controller anyway.

OCZ has been pushing some new and unusual heatsink designs for some time now. First they came up with the XTC (Xtreme Thermal Convection) heatspreaders. These heatspreaders allowed for increased ventilation and heat dissipation, due to the honeycomb design that provides more direct access to the actual memory ICs.

The XTC heatspreader design was quite simple really, and since then OCZ has come up with more exciting designs that move away from traditional heatspreaders to use heatsinks. Possibly one of their most exciting series that has seen a few design changes over the years is the Reaper series. The DDR3 PC3-12800 Reaper HPC memory modules use the latest design and it looks quite impressive.

The Reaper HPC heatsink is designed to extract the heat away from the memory chips, up through a thermo-conductive copper heatpipe conduit, and then dissipate it through an aluminum fin array. By guiding heat away from key memory components, the Reaper HPC modules are designed to boost overclocking performance, while improving longevity and stability of the modules.

Not only do the Reaper HPC heatsinks look impressive, but they also have a few advantages when compared to other modules using large heatsinks. Despite looking quite large, they are actually very compact, and can easily fit side by side. Height wise the Reaper HPC design has the potential to create compatibility issues with certain components, though this would only be in rare cases.

Hardware - Intel Core i7 965 Extreme Edition (LGA1366) - OCZ Reaper HPC PC3-12800 (6GB) - A-Data XPG Plus PC3-12800 (6GB) - G.Skill Trident PC3-12800 (6GB) - Patriot G-Series PC3-10666 (6GB) - Patriot G-Series PC3-12800 (6GB) - Seagate 500GB 7200-RPM (Serial ATA300) - ASUS GeForce GTX 285 (1GB) - Asus P6T Deluxe (Intel X58) Software - Microsoft Windows Vista Ultimate SP1 (64-bit) - Intel System Driver 8.4.0.1016 - Nvidia Forceware 185.85 WHQL

When running the SiSoftware Sandra 2009 memory bandwidth performance test we found that DDR3 memory clocked at 1600MHz was capable of delivering a throughput of 27GB/s. Despite the difference in timings between the modules tested at this frequency we saw just 700MB/s separating the fastest and slowest DDR3-1600 memory.

The OCZ DDR3 PC3-12800 Reaper HPC was one of the fastest kits tested, producing a memory bandwidth of 27.50GB/s, making it the second fastest tested. Included in the comparison is the G.Skill Trident memory which uses slightly more aggressive timings of CAS6-7-6-18. Still just a little over 200MB/s separated the Reaper HPC and Trident memory.

When testing with EVEREST Ultimate Edition the OCZ DDR3 PC3-12800 Reaper HPC memory was actually found to be slightly faster than the G.Skill Trident. Nevertheless, once again we saw very little difference in bandwidth performance when comparing memory using CAS6-7-6-18 to CAS9-9-9-24 for example.

Finally the last synthetic memory bandwidth test that we used was PCmark Vantage, and again this software gives the OCZ DDR3 PC3-12800 Reaper HPC the edge, despite using slightly less aggressive timings when compared to the G.Skill Trident.

Here we see that the weaker timings of the Patriot DDR3-1600 memory hurts it, as the WinRAR multi-thread performance reached just 3569KB/s, making the OCZ DDR3 PC3-12800 Reaper HPC memory 11% faster. The lower latency DDR3-1600 memory all produced roughly the same result, which is not surprising given that they all delivered similar bandwidth performance.

The Super PI performance is very much the same with all DDR3-1600 configurations, with very little difference between the best and worst result.

Finally we have CINEBENCH R10, and again the results are very much the same. That said, the OCZ DDR3 PC3-12800 Reaper HPC did do well, producing the best OpenGL and Multi-GPU rendering results.

This is where expensive DDR3 memory and the Core i7 platform do not make a whole lot of sense. Given that most games are predominantly GPU limited, slightly more memory bandwidth for the CPU is going to make very little difference. While a few more frames per second can be scored at the lower resolutions, at the resolutions that we are likely to play our games there is virtually nothing to be gained.

When clocked at 1333MHz we were able to run the OCZ DDR3 PC3-12800 Reaper HPC at CAS6-6-6-16 timings, which is about as low as you will get any DDR3 memory. Then by increasing the memory multiplier and the base clock, we were able to reach a maximum operating frequency of 1822MHz with CAS9-9-9-24 timings.

The low latency DDR3-1333 configuration was slower when testing with WinRAR when compared to the standard configuration, while the overclocked 1822MHz configuration was much faster. When testing with Unreal Tournament 3 this all made little difference, and at 1920x1200 it was the standard configuration that worked the best, albeit by 1fps.

The problem is, while we do see quite a large increase in available memory bandwidth when going from triple-channel DDR3-1066 to DDR3-1600 memory for example, this bandwidth does not necessarily make for better performance. Games for example, will see just a frame or two extra when jumping from DDR3-1066 to DDR3-1600. However applications such as WinRAR do see decent performance gains, so really it depends on what your requirements are.

Based on our findings over the past 7 months or so, it does seem as though DDR3-1600 memory is ideal for the Core i7 processors, and it will unleash their full potential. That said, DDR3 memory clocked at 1066/1333MHz is not a great deal slower and will deliver practically the same experience. Today there is as little as $20 US difference between DDR3 clocked at 1066MHz and 1600MHz, so picking between the two is becoming less of an issue.

For roughly $100 US it is possible to purchase DDR3-1333 memory that can work with CAS7-7-7-18 timings or DDR3-1600 memory that works at CAS9-9-9-24. So really they are very much the same these days. However if you spend a little more, around $140 US, the OCZ DDR3 PC3-12800 Reaper HPC memory kit is an interesting option, as it offers low latency timings at 1600MHz.

There are plenty of DDR3-1600 memory modules that support CAS8 timings for around $20 US less. However few modules that work at this frequency can match the impressive timings of this OCZ memory. Therefore, if anything the OCZ DDR3 PC3-12800 Reaper HPC memory is a unique product. Additionally, it is also quite an exciting looking product, and the Reaper HPC heatsinks do help keep this memory cool when overclocked.

When fine tuning these memory modules we were able to reach a maximum stable frequency of 1822MHz, which is a decent 14% overclock. Furthermore, when operating at 1333MHz we were able to tighten the timings up to CAS6-6-6-16, which was quite remarkable and showed the OCZ Reaper HPC memory to be highly flexible.

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Reviewed By Steven Walton