FSB change and HD


I have 200 FSB on my Prescott 3.0, but I wanted to raise FSB a bit to 215. OC went fine, but IDE device listing did not recognize my hard disk, which is on S-ATA controller and recognized as master on secondary channel (is that even normal?) when CPU is on default or user defined 200 x 15. Every other value makes my HD disappear. Any idea?

That’s not so stranged. If your IDE/SATA/RAID etc controller is attached to the PCI bus and your PCI bus isn’t locked at 33Mhz, the busspeed is raised when the FSB is. This means that raising your FSB to 215Mhz, your PCI will be running at about 36Mhz. Yes, that’s only a 3Mhz difference, but it appears to be enough to upset that controller.

The best solution would be to lock your PCI (and AGP) bus. If your mainboard allows that of course. Have a look in your BIOS or mainboard manual I’d say. Or, supply us with the brand, type, revision and bios version of your mainboard…

I have set the PCI/AGP speed to 66/33, so the ratio is 6:3:1, like it was in auto mode. Right now it is running at 225 FSB, the temp hasn’t changed … Strange. Now it has 3.38 and no difference in temperature between now and 3.00. Maybe I should OC it just a tiny bit more. :wink:

When idle, the temperature should be pretty much the same, but under full load, some change should be noticable, esp since the P4 Prescott is a real hotheaded CPU.

Did you do any stress tests? If not, I’d be very wise to do so… :wink:

When OC’ing, upping fsb will of course make the cpu run faster which will mean some more heat, depending on how much faster you make it run. But what actually really makes the heat change alot, is if you up the vcore voltage to the cpu so you can get an even higher OC, which alot of people do. In alot of cases, just making the cpu run faster but not changing the voltage, may not affect heat all that much, as you just noticed :slight_smile: .

And when OC’ing, monitor those temps! And like dee-ehn said, you really should do some stress testing to make sure your stable. Just cause you can boot and use the computer, doesn’t mean it’s stable. :slight_smile: