Over/Underclocking Ripjaws X F3-14900CL10D-16GBXL DDR3 1866

[devoh]

Howdy,
I'll be honest.. I'm a newb.

I purchased G.SKILL Ripjaws X Series 16GB (2 x 8GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-14900CL10D-16GBXL for an Asus Z97 Pro Gamer motherboard with an i7 4790k.

I'm curious if anyone has underclocked these to DDR3-1600 and what timings they were able to get? I hear on the Z97 chipset there are greatly diminishing returns on overclocking and that dropping the timings as low as they can go can sometimes gives you more benefit.

So I was just curious what others were able to achieve. My last rig was a intel E8500(dual 3.15Ghz) with DDR2-800 (6 years and 2 months old).. so I'm having to learn all about overclocking.

Thanks

-D

[emissary42]

I hear on the Z97 chipset there are greatly diminishing returns on overclocking and that dropping the timings as low as they can go can sometimes gives you more benefit.

It is actually exactly the other way around. Clock rate is more important than timings up to a certain point. You will see 50+% gains in synthetic bandwidth going from DDR3-1600 to DDR3-2400 and the overall latency will be about 20-30% lower as well (even with relaxed timings of 11-13-13-31 @ DDR3-2400).

I'm curious if anyone has underclocked these to DDR3-1600 and what timings they were able to get?

If you want to tweak timings for DDR3-1600 anyway try primary timings

9-10-9-24
9-9-9-24
8-9-9-24
8-9-8-24
8-8-8-24
7-8-8-24
7-8-7-24

and see how far you can progress. Raising the Vdimm might help a bit, depending on the type of ICs G.SKILL used on your kit. Manually adjusting the secondary and tertiary timings is a lot of work and while it can improve performance a bit, it is not really worth it at DDR3-1600 in my opinion.

[devoh]

It is actually exactly the other way around. Clock rate is more important than timings up to a certain point. You will see 50+% gains in synthetic bandwidth going from DDR3-1600 to DDR3-2400 and the overall latency will be about 20-30% lower as well (even with relaxed timings of 11-13-13-31 @ DDR3-2400).


If you want to tweak timings for DDR3-1600 anyway try primary timings

9-10-9-24
9-9-9-24
8-9-9-24
8-9-8-24
8-8-8-24
7-8-8-24
7-8-7-24

and see how far you can progress. Raising the Vdimm might help a bit, depending on the type of ICs G.SKILL used on your kit. Manually adjusting the secondary and tertiary timings is a lot of work and while it can improve performance a bit, it is not really worth it at DDR3-1600 in my opinion.

Thank you for the info, figures I'd get it backwards. lol

So naturally my next question is what can I expect or should I try for in overclocking it?
Any chance of hitting DDR3-2400? What timings should I try? I assume a Vdimm of 1.65 is probably needed as well.
or was this the answer already "(even with relaxed timings of 11-13-13-31 @ DDR3-2400)"?

Thanks for the help

-D

[emissary42]

...or was this the answer already "(even with relaxed timings of 11-13-13-31 @ DDR3-2400)"?

Just try it

I can't really tell you if it is possible. That does depend on the ICs used on your kit.

You could also try DDR3-2133 11-11-11-28 first at 1.5-1.6V.

[GSKILL TECH]

Z97 and Haswell has the least~ diminishing returns..