I was hoping to get this rig running on a 200mhz FSB speed (default 166mhz) but it's just not happening for me.

It boots fine at 200mhz, but crashes at Op Sys (XPproSP2) load. It runs cool and fine right up to 2388mhz with FSB @ 191mhz

At 2414mhz Win XP gives me the "driver less than or equal to" (or was it greater than or equal to?) error blue screen of death, I figure windows crashes at 2.4 ghz for some reason, and the reason is windows protection software of some kind. If I clock at 2388 for instance, A line frequency power change from my mains power is enough to tip me over 2.4ghz and crash my system to blue screen again.

Am I right about this?





RAM is PC3500 Kingmax

At current settings I've set my ram to: 7-3-3-2.5,  6-3-3-2.5, or 5-3-3-2.5

benchmark results at 7-3-3-2.5  are the same or faster than the other settings above so I leave it there.



I'd like to know how to set the RAM timings up correctly rather than just by accident, is there a method? Can I use the util in the pic, or another util to tweak the timings on the right side there? I dont see those timings in bios, all i see in bios is the usual 4 settings ie ....  7-3-3-2.5
Would tweaking those hidden timings make any difference.

Increasing Vcore and RAM voltage often produces boot failure, though the PC3500 should cope fine on my rig. (2x512mb modules in dual channel configuration) I have default voltages set except when experimenting.

BIOS shows an optimal or aggressive CPU interface setting which I can't figure out, but it says set to aggresive for o/c and something else that's a bit ambiguous. Anyone know what this is for ?

I run the ram in sync with my CPU and FSB speed, so it should be underclocked, and if set to SPD, the ram configures well over 200mhz by itself, so I wind it back to match the FSB speed.

My cpu is running faster than a XP3200+ already and scores benchmark figures in excess of 3200+ comparison data. My memory bandwidth is slightly down from the 400mhz rigs (lower FSB speed here).

I suspect that a 64bit PC upgrade will not yield me any major CPU performance increase as the clock speed is about the same as what i have now, though I realise my memory bandwidth will go way up.

My two main apps need more CPU power, that's what I'm after.  Everything else seems to be coping fine. Have I taken this rig as far as it will go?

Could I improve things by adding an XP3200+ and trying to overclock that in excess of it's stock speed of 2.2ghz? I mean, I'm already at 2350mhz! I heard they don't clock much beyond 2.4ghz anyway.

Has anyone had an upgrade to a 64bit rig from a system like mine (nForce2 ultra400 chipset) and gotten better CPU performance?

PC is air cooled, and yet temps are low and stable. So heat doesn't seem to be involved yet.

I must be missing something, as the usual methods of upping voltages bit by bit to obtain stability seem to immediately fail.

Ivan, I have the most advanced Socket A chipset/mainboard, it has full 266/333/400mhz support and overclocking ability.

It was a big improvement on the via kt400 chipset which you have.

My CPU is 333mhz default and is one of the later thorton cored Barton's.

The PCI and AGP and memory bus speeds are independent of FSB. (locked or adjustable).

I'm sorry but you seem to lack knowledge about these chipsets in general, I need more advanced help....

Thanks all the same.  8)

Congo, for some of the best Overclocking advice, I'd talk to these guys here....

http://forums.overclockers.co.uk/forumdisplay.php?f=7

I guarantee, with your post style, you'll get help. 

RAM is not the issue. (what is your RAM speed? Not FSB, but actual RAM speed, sometimes different)

You have 1 of two things stopping you from furthering your speed:

1. Your CPU has found it's limit and will not overclock to anything faster than about 2350MHz

2. With your FSB set up at 166, and upping it from there, you are overclocking your PCI/AGP bus well beyond the 33/66 that it is supposed to be.


Now, I see you have an nForce2 chipset, what motherboard is it? There are a very few that do not allow AGP/PCI locking (some early models and OEM's) which would cause that problem.

But your symptoms are exactly what my XP2100+ (1733MHz, pre hard-locked T-Bred 'B') would do after I pushed it past 2420ish MHz. Even cooling it to below freezing temperatures it would puke with the same message.


-8C/18F is CPU temperature, the other is mainboard temp.

10X minimum, I'm looking at the 11x model though. My current one is maxxed out with the 9X multiplier.

As for your computer booting fine at 2500, but won't start windows:

The CPU has reached its limit. It will boot, the CPU works mostly, but when it tries to do anything (start windows), it does incorrect calculations ect. Exactly like overclocking your GPU too much. It works, but you get artifacts. Well, windows doesn't like CPU artifacts, really messes it up. I've even corrupted information on the hard drive when having the CPU too fast....

Thanks for that