cant raise FSB

wololo · Post by **wololo** » 18 Apr 2006, 19:00

I tried to over clock my Athlon 64 3200+ by slowly raising the FSB it all worked great untill i got to 215 then the pc wouldnt boot.So change of plan i tried to use the fairly idiot proof easy tune 5 that came with my pc same prob just froze and came up wit blue screen.Im pretty sure it not the temp coz it runs very cool to the touch.so i thought maybe power.What do you guys tink?got 300w psu!

DAE_JA_VOO · Post by **DAE_JA_VOO** » 18 Apr 2006, 19:12

Well, first off:

We need all the specs of your system. Well, not all, but motherboard, RAM, and what brand of power supply. The power supply and RAM are very important in OCing...

Bobendren · Post by **Bobendren** » 18 Apr 2006, 19:12

Reduce the LTD multiplyer to 3x, this will reduce the FSB to 600. General rule for AMD - don't exceed an FSB of 1000.

Also you'll need to use a memory divider to reduce the speed of the memory.

wololo · Post by **wololo** » 18 Apr 2006, 19:18

eish sorry heres specs 512 ddr 400 corsair gigabyte K8 Nforce 4 mobo

wololo · Post by **wololo** » 18 Apr 2006, 19:20

Bobendren how can it reduce fsb to 600 wen it only on 200??soz if this a dumb question!:)

DAE_JA_VOO · Post by **DAE_JA_VOO** » 18 Apr 2006, 19:21

What PSU have you got dude?

wololo · Post by **wololo** » 18 Apr 2006, 19:22

Aopen 300w (soz tort i said dat already)

DAE_JA_VOO · Post by **DAE_JA_VOO** » 18 Apr 2006, 19:45

Yeah, okay the PSU isn't the problem.

Bobendren · Post by **Bobendren** » 18 Apr 2006, 22:30

wololo wrote:Bobendren how can it reduce fsb to 600 wen it only on 200??soz if this a dumb question!:)

Not at all. On AMD systems the FSB is known as the HTT for some arb reason. So on a standard non-overclocked Athlon64 rig:

HTT= 200MHz
LDT Multipler= 5
FSB= 1000MHz (200x5)
HyperTransport = 2000MT/s (1000x2, coz it's DDR Ram)

MT/s stands for Mega Transfers per second and doesn't really mean anything, so you can ignore that one.

By lowering the LDT multiplier (not to be confused with the CPU multiplier) you reduce the FSB and so create headroom for overclocking, because as previously stated exceeding an FSB of 1000 is badong i.e you can corrupt your installation of Windows.

Post by **maxxis** » 18 Apr 2006, 22:41

How can you check inside windows what you FSB is at?

Bobendren · Post by **Bobendren** » 18 Apr 2006, 22:43

Use CPU-Z

edit: http://www.cpuid.com/cpuz.php

Post by **maxxis** » 18 Apr 2006, 22:58

Oh yeh. True.

Post by **maxxis** » 18 Apr 2006, 23:00

What I mean is the actual HTT 1000 or whatever its call.

Reason I ask is because my CPU is at 2500 250x10 and I cant remember setting LDT to 4x

cYcLIc · Post by **cYcLIc** » 18 Apr 2006, 23:09

Use CBId (Central Brain Identifier). It will be under HTL Speed. It's like a more detailed version of CPU-Z.

CBId Download Page

Get Version 8.0.0.2 Build 0406.

Bobendren · Post by **Bobendren** » 18 Apr 2006, 23:15

ctrl-alt-del wrote:What I mean is the actual HTT 1000 or whatever its call.

Reason I ask is because my CPU is at 2500 250x10 and I cant remember setting LDT to 4x

It's probably set to auto in which case your motherboard did it for you.

As a matter of interest some ATI chipset based mobos can handle an FSB up to 1500MHz.

Hex_Rated · Post by **Hex_Rated** » 18 Apr 2006, 23:39

As a matter of interest some ATI chipset based mobos can handle an FSB up to 1500MHz.

R580 chipset A8R32 can do it. I think the older R480 couldn't get near that. Which gives a OCd HTT bandwidth of 12GB/s ( instead of 8 ). Will be interesting to see them running DDR2-800 at 1:1 dividers on the AM2 socket. This should allow them to use the full bandwidth of the memory in dual channel (12.8 Gb/s).

@wololo: It's definately your LDT multiplier causing problems. Look for it in the BIOS. Its sometimes called an HTT multiplier, at least on ASUS mobos anyway. Rather use clockgen and increase in 1Mhz increments with Prime95 running in the background. You will see exactly when it starts to fail without crashing the PC. Also, set your RAM divider to something lower than 1:1.

wololo · Post by **wololo** » 21 Apr 2006, 16:11

thanks hex but i only now managed to get back into windows (crashed and wouldnt come back on!:) so wont be tryin that for a while thanks anywa!:)