How low should my tRAS go?

[doesitmatter]

I just built myself a new Ivy Bridge rig along with 16GB (4x4) of ram rated at 1600MHz, 9-9-9-24. I've been able to tighten timings at that frequency to 8-9-8-x where x has been able to boot at as low as 12. All the RAM overclocking guides I've been reading suggest that tRAS should be somewhere in the neighborhood of the total of tCL, tRCD, and tRP combined (25) without noting why or if going lower than this threshold is advisable. So, my question is whether or not I should be taking my tRAS as low as I can get it, or if I should be sticking to approximately that threshold, and what tRAS you would recommend at these timings? Thanks!

 

[jaquith]

About as low a you 'can' reliably go is CAS+TRCD or you'll be throwing errors; or 9+9=18 or 8+9=17. (CAS-TRCD-TRP-TRAS)

Frankly, I'm surprised the BIOS during post didn't drop out.

 

[doesitmatter]

I was extremely surprised too, it just kept booting at lower and lower timings, I actually stopped at 12, it might have booted at even lower timings. This is actually why I asked this question, I was expecting it to 'bottom out' like the other timings had done and that would be that.

I managed to find the following excerpt in my search: "According to Mushkin.com, in practice for DDR SDRAM, this should be set to at least tRCD + tCAS + 2 to allow enough time for data to be streamed out." Seems reasonable, also considering my sticks are from Mushkin. Thanks for your help with this, jaquith.

 

[doesitmatter]

Best answer selected by DoesItMatter.

 

[nikorr]

This topic has been closed by Nikorr