G.Skill DDR3-2200 C7 Synthetic performance
Note:
Today we'll do things a little differently. Since we are talking about memory that can actually run at 2200 MHz, we will lose the ability to objectively measure real-world performance. Here's the deal, to achieve a 2200 MHz memory frequency, we will have to tweak the base clock of the processor, and that will overclock the processor as well.
As such we will throw in synthetic testing done with Everest where you can observe memory performance really precisely. And then we'll just compare test results absed on 1333 CAS( (JEDEC) timings and the combo of really fast memory at 2200 MHZ CAS7. All at an overclocked processor.
We'll take a Core i7 870 processor which has allows 2:12 memory ratio, needed to enable 2200 MHz in the BIOS with the help of the embedded XMP memory profile. If interested, the Core i7 860 has this as well, the Core i5 750 does not.
G.Skill DDR3-2200 C7 with a Core i7 860/870 processor
So let me make this clear once more, should you by any chance have a Core i5 750 processor then be aware of the fact that the Core i5 750 has a limited memory ratio of 2:10. The reality is that if you seriously consider to purchase this memory, you really would like to have Core i7 860 or 870 processor as it will allow you to take that memory frequency up a little more as the limit is now raised to 2:12.
I'm not saying that it isn't possible with a 2:10 ratio on the Core i5 750 -- it's just much harder to reach. Above such an example of near 2200 MHz on the memory with a 2:10 memory ratio. If we increase the base clock even 2 MHz upwards .. we are crashing the system :)
So in the BIOS we can just flick on the XMP profile and at default we'll have the memory running at 2200 MHz CAS 7:10:10:28 1T without any complex CPU overclocking. Our MSI Big Bang motherboard reads the memory XMP profile and applies optimal settings accordingly. It however refused to boot into windows until we increased voltages on processor and PCH manually.
Selecting the XMP profile includes an automated tweak of the multiplier and baseclock. For this review we however will overclock manually due to the BOOT issue just mentioned.
With the Core i5 750 processor you will run our of juice at roughly 2000~2100 MHz on the memory within a normal overclocking baseline. And that's just not the case with say a Core i7 860/870 processor. Anyway, have a look at the embedded timing profiles in this memory.
Do you see that XMP-2200 profile? If you have a decent motherboard, the BIOS will allow you to load up and apply that profile in the BIOS. You need the 2:12 memory ratio available though, and that's what the Core i7 860/870 processors allow. Downside -- your system will start to get overclocked as the profile requires the baseclock to be run much higher.
So there's no way of running this memory at 2200 MHz with a default clocked processor (133 MHz base clock) -- make no mistake, overclocking is a requirement.
By having this as options -- we can now run tests in-between standard 1333 MHz and 2200 MHz a little more reliable (still subjective). This little tidbit will be all about the actual performance difference measured in-between the memory frequency.
Once you overclock the CPU, base clock, voltages you could and end up at something like 183 MHz host / base clock --> 183x12=2200 MHz DDR3 memory.
We decided to go for a massive CPU overclock and then benchmark at 2200 MHz and 1333 MHz on the memory to measure the performance differential.
So here we have the memory screaming at 2200 MHz. And yes this is CAS 7:10:10:28 and a command rate of T1 -- we have VDIMM voltage towards 165v at this stage. The result is absolutely stunning at over 20.000 MB/s read performance ! But let's check out the memory write performance.
Here you can see the memory clocked at 2200 MHz CAS 7:7:7:28 yet now you can spot the write performance. How frickin amazing is that ? BTW we have a massive overclock on our hands here. The increased base clock obviously effects write performance.
Let's have a look at some charts and games.
