Precision 7710 + DDR4 2666: it works with G.skill Ripjaws !

http://www.gskill.com/en/product/f4-2666c18d-32grs
F4-2666C18D-32GRS

When they will available again, I will buy the second block of 32gb.

They work and the speed seems to be correctly recognized from the bios.

But from the performance perspective I have some doubts. Compared with my ex M6700 (i7 3740 and 32 gb DDR3 1866mhz Corsair), 1Mb SuperPI test is slower almost than 1" (9"9 M6700 vs 10"7 7710) while I did a short test with stock 2133 DDR4 Dell gave me and I got 10"4.
Anyway where do I expect advantage of 2666 vs 2133 and which test can I use to check it?
Is it possible the speed impact is always less important than the deterioration of the cas latency?

Or maybe we have to expect a new bios version that officially support them and so after the performance will improve? (possible?)

Thanks

My config: 7710, i7 6820HQ, 2x16gb DDR4 2666 Ripjaws, IGZO 4k, Quadro M3000M, 1xM2 950 Pro for Win10 pro, 1x Seagate ST2000LM003 5400rpm 2TB, , 6 cells 91Wh

 

CAS latency has to do with the number of cycles that it takes for the memory to service a request, it is possible for faster memory with high CAS to service requests slower than a slower memory with low CAS. You can't compare the CAS directly if the speeds are different, you have to do something like (CAS ÷ speed) to get a comparison between the modules (lower is better).

Not sure what the CAS latency of your old modules was but it looks like your new ones are 18 at 2666 MHz? A latency of 14 at 2133 MHz would be just slightly faster, and 13 would be even more so.

I seriously doubt a BIOS upgrade would affect this at all. The memory operations are handled by the memory and CPU only.

 

DDR3 were Vengeance, C10
I agree with you @Aaron44126 but, at today, usually you pay the higher frequency speed with worser CAS.
But I thought in some way I would have had some advantage taking 2666 C18 instead of 2133 C15...

If not, I can evaluate to send back this ram and take 2133 C15 Rpjaws that have lower CAS of course....