This is my first time trying to do a major overclock, and the Gigabyte BIOS is driving me nuts. First, the basics:
CPU Q6600 G0 SLACR (lapped)
MB: Gigabyte GA-X48-DQ6 (unfortunately, it's so new that its hard to find info on)
cooler: Xigmatek HDT-S1283 (also lapped)
PSU: PC Power and Cooling S75Qb 750W
video: Zotac GeForce 8800GT 512 MB
ram: G.Skill 4 GB (2x2gb) DDR2 1066 (mfr. specified voltage is 2.1, with 5-5-5-15 timings, when the motherboard is set to autodetect timings, it gets 5-7-7-20, right now I have it dialed in to the recommended 5-5-5-15)
fans: 5x Thermaltake A2016 80mm variable case fan
I'd like to overclock the chip to 3.6 GHz (from 2.4) by raising the voltage to about 1.48 and the FSB to 400. When I do this, the computer posts and boots, but as soon as a start a Prime95 stress test, the computer restarts in a couple seconds.
I *think* the problem is in my RAM settings. Apparently the RAM settings on the Gigabyte bios are somehow tied into the FSB settings, but I don't understand how. (i.e. changing my FSB to 400 does strange things to my RAM, such as making it run at 1200 rather than 1066, etc)
My question is this:
What should I set my RAM System Memory Multiplier (SPD) to in the BIOS when I overclock the Q6600 to 3.6 (400 FSB)? What about with the processor at 3.4 (If 3.6 will not work with my components - although I REALLY hope it will)
The SPD menu (used to set RAM frequency) is set as follows (and only contains these choices):
Auto, 2.00A, 2.50A, 3.00A, 4.00A, 2.00D, 2.66D, 2.00B, 2.40B, 3.20B, 2.66C, 3.33C, 4.00C
The explanation for this menu reads as follows:
Auto -> Set memory frequency by DRAM SPD data
(G)MCH strapping: x.xxA -> FSB 266 MHz; x.xxB -> FSB 333 MHz; x.xxC -> FSB 200 MHz; x.xxD -> FSB 400 MHz
Should I run this RAM lower? Higher? Get different RAM? Will it help to underclock the RAM? How? I don't understand how to 'fix' the RAM problem when I OC the CPU.
Quick summary: What SPD memory setting should I use with 1066 RAM when overclocking a Q6600 to 3.6 GHz (400 FSB)? What about 3.4 GHz? (378 FSB I assume)
Thanks for the help! (and tell me if I need to post anything else)
Also, if anyone has experience with this motherboard/general cooling setup, is 3.6 GHz stable a reasonable goal? Or is that only likely if I get a reallly lucky set of parts? Anything else I should try?
The FSB/voltage/overvoltage are what i have at the moment - still onfused a bit on SPD though...
by SPD: 2 do you mean: 2.00A, 2.50A, 2.00D, 2.66D, 2.00B, 2.40B, 2.66C
I assume since I'm running at 400 FSB, I need 2.00D or 2.66D?
Which one? 2.00 would give me 800 MHz, whereas 2.66 gets 1066 right? The ram is rated for 1066, but this doesn't say anything about the CPU FSB. Am I better off leaving it at 2.00 until I get everything else working, then up it to 2.66?
Finally, in case I can't get 3.6 GHz working, what do I set the ram to for 3.4? (seeing as how none of the SPD options correspond to a 378 FSB)
Also, the VID of my chip (according to Core Temp, nonoverclocked): 1.3000v
The cores run at about 40C nonoverclocked. (for some reason, 0 and 3 seem to be running much hotter than 1 and 2)
Edit: even without overclocking, using motherboard defaults, as soon as I start Prime95 the core temps jump from 35-39C to 73C and keep climbing (I stopped it then). That CAN'T be good!
Any ideas on what's going wrong? Maybe I put too little thermal paste on? Or too much? I though the idea was to put on as thin a layer as possible, especially with lapped parts?
The idea is a thin layer. I recommend testing how much is making contact with the heat sink. Simply remove it by pulling straight up on the heat sink gently until it slips off, and you'll easily be able to see if its making proper contact with the chip.
Got anything around the socket like high capacitors? I lapped one chip a bit low because it was sloped, and that made it where the water block I had didnt fit properly, had to get a smaller profile one, because the old large one rested on some capacitors that were right around the Fing socket. Nice formula maximus design, Asus!
Sometimes it can even look like it made contact, but all it was able to do was contact the paste lightly, and not stay forcefully against it.
That can also explain your weird temp differences in the cores. I have had 10 q6x00s and they all were within 5 c of eachother, max when Idle. Some were very close, and I have one that when loaded, all 4 cores always are the same!