penguinpoo, 17165 3D marks is just awesome IMO. Congratulations man!
Also, HOLY ****! Where did you buy your SINXP?? I thought that board just came out. I didn't know that you could buy one right now. I checked Gigabyte's website and it is saying that the board is available right now and also that it supports dual channel DDR 400. *whistles* (altough doesn't the SIS655 chipset officially support *only* dual chanel up to DDR333?).
For your problem, In terms of the CPU voltage, what you are saying indeed sounds very strange as if you are running competely stable at 169fsb (Prime 95 and stuff runs without errors), then THERE IS NO WAY that increasing the FSB by just 1 mhz will make the PC unbootable. What can happen is that the PC can become unstable but it is unheard of for a PC to go from 100% rock stable to unbootable by just increasing the FSB by 1 mhz. As a result, you CPU is definately not the problem here!
One thing I wanted to ask about this problem was whether you had the ability to lock your PCI and AGP buses with your motherboard and if so, whether you were doing this already or not. As it is, IF your AGP and PCI buses were running without dividers (I am typing this because I didn't see on Gigabyte's website if the board allowed you to lock the PCI and AGP buses), then at 169FSB, they would be at 84.5Mhz and 42.25Mhz respectively. Perhaps this is the limit for one of your PCI cards (sound card, NIC, *Hard Disk*, etc.) and therefore when you increase the clock speed by even 1 mhz, the PC stops booting up. There is also another possibilty in this regard. Being such a kick-*** board, now I think about it, the SINXP must have an AGP and PCI lock but maybe this feature is not working with the current BIOS!! As a result, try updating your BIOS to see if it helps.
The RAM could also be the problem. It is unlikely, altough possible that the 1mhz increase (which will be a 2mhz increase for DDR at 1:1) makes the RAM unstable at the timings you are running it at.
I'm curios about one thing though:
im keep the ram close to 400 and 3-6-3-3 timings,
Hmmm, if this is the case, then you are running with something other than 1:1 or 3:4 or 4:5 as none of these ratios would make the RAM run at around 400mhz at 169fsb. The board you have must have other ratios then. What ratio are you running at?
Well, regardless of what ratio you are running at though, try dropping the ratio to 1:1 just to see if the PC will boot then. If it does, then the RAM is the problem.
You should also know that increasing CPU voltage will never get rid of artifacts you see on the screen. Artifacts are strictly related to the graphics card. If you overclock just your CPU, you will never see any artifacts. You can only see artifacts if you overclock the graphics card so if you do see artifacts at one point in the future, just play with graphics card clocks and don't touch the CPU voltage. Also, you can safely increase the CPU voltage up to 1.75V's. Anything above is considered dangerous by certain people altough there is no evidence whatsoever to support this. As you can see in my sig, I have been running at 1.85V's for over 3 months now and didn't experience any problems at all...
Im using the SINXP and 2xXMS3200LL RAM [after success of mine, i was rather dissapointed]
