Overclocking / Clocking / Underclocking

eXistenZ

Distinguished
Nov 6, 2011
169
0
18,690
In order to study algorithm performance this fall – O( n * log n ) et cetera – I want to create three profiles which run the CPU at three speeds: 1.5, 3.0, and 4.5 GHz. And I want the computer to run at those speeds constantly. When I run the algorithm, I don’t want the CPU going from 1.6 GHz up to 3.3 or 3.7 GHz, and then back down to 1.6 GHz. And ideally, I would be able to change from one profile to another from inside the OS without having to reboot into Bios (does Ai Suite allow this?).

I went into the ASUS UEFI bios and simply set the multiplier at 4.5 and it gave me a stable overclock on Prime95 for a few hours keeping the temperature in the mid sixties, so I assume I can get a legitimate 4.5 OC on this system.

Does anyone know if this is possible? Is it the same problem as finding a stable OC at 4.5, but set the multiplier at 1.5 ? And how do you prevent the CPU from going from 1600 to 3300 or 3700, I haven’t found that info anywhere. (Noob 2 OC).

Any any advice on how I can go about accomplishing this is greatly appreciated.

I5-2500k / ASUS P8Z68-V / 212 Evo in-out / Gskill 1600 2x4 / Corsair TX750v2 / Win7
 

eXistenZ

Distinguished
Nov 6, 2011
169
0
18,690
I turns out that the i5 cannot go lower than 16x. So I decided to go with 2.2 / 3.3 / 4.4 GHZ settings. I just created the profiles in bios and I'll leave it at that.

I found that the c-states worked when I set them at Auto. When they were at Enabled, the Speedstep and Turbo selections didn't seem to work, as though they were overridden. So by selecting Speedstep and Turbo to Disabled and setting 22x or 33x, I got the first two points, and then setting Turbo 44x (1.28 VCore Manual) I got the third performance point that I was after.

I had hoped that it would be possible to dial-in those criteria from software, but I'll just reboot and play it safe. My temps are mid-40s, -50s, -60s.

Thanks.