Our Christmas treat at the end of last year was a review of some super-fast super-expensive Kingston KHX11000 DDR3 memory. The clock speed of 1,375MHz was impressive but on the face of it the speed wasn't fast enough to keep up with the new QX9770 Penryn which runs on the new 1,600MHz front side bus.
In fact that's not quite true as the KHX11000D3LL has a true speed of 688MHz which is considerably faster than the true 400MHz front side bus of the QX9770. Ah the joys of DDR memory speeds and a quad-pumped Intel front side bus.
The past few months have seen the introduction of faster DDR3 memory speeds and new chipsets from both Intel and Nvidia. The new must-have speed is 1,600MHz while overclockers will pander after memory that runs at 1,800MHz or 2,000MHz. Kingston has come up with a 2GB kit that has the model code KHX13000D3LLK2 with the same 7-7-7-20 latency figures as KHX11000D3LL. The only difference in the specifications, apart from the clock speed, is that the new memory requires a voltage of 1.9V to hit 1625MHz where the older memory ran at 1375MHz on 1.7 Volts.
Cosmetically the two models of memory are identical with understated blue anodized aluminium heat spreaders that have some shiny machined areas that include the HyperX logo.
You may be wondering about the numbers in the model codes as the figures of 11000 and 13000 are slightly cryptic. They refer to the bandwidth of the memory which increases as the speed gets higher so the 1375MHz memory has a bandwidth of 11GB/second and the 1625MHz memory has a bandwidth of 13GB/second. Although they are large and impressive numbers I can't help but feel that Kingston, or any of the other memory manufacturers, would do us all a favour if it put the emphasis on clock speed rather than bandwidth. After all, you adjust the memory speed in your BIOS and don't give a second thought to the bandwidth figure.
We had previously tested the KHX11000D3 on an Asus P5K3 Pro, which use the Intel P35 chipset, but a far more tempting prospect was available for the new KHX11000D3. The motherboard in question is an Asus Striker II Extreme that uses an Nvidia nForce 790i Ultra SLI chipset, which supports the latest Intel Penryn processors with memory speeds up to 2,000MHz.
In addition to the usual voltage adjustments the 790i Ultra has another string to its bow as you can choose whether the memory speed is linked to the front side bus. If the speeds are unlinked you can adjust them independently instead of the usual situation where you use a multiplier to adjust the memory speed relative to the front side bus.