A7V Overclocking

KurtD

Member
Aug 17, 2000
107
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I OCd my Tbird 750 on the A7v using the dip swithches to set the multiplier to 9x. I left the dips at 9x then reset the mb to jumper-free. It now posts at 900 and allows me to modify the bus speed and voltage in bios. I have observed that when leaving the voltage on "auto" it seems to be somehow compensating for the higher clock multiplier since Probe reports Vcore at 1.792 - I have the voltage jumpers in their defalut settings. I haven't read anything about this feature anywhere. The system is much more stable on "auto" under this configuration than when I try to set the voltage in bios manually or using the jumpers. 900 seems to be my limit with this CPU. One odd thing is happening - when I turn the power on the computer powers-up but does not boot. I have to hit the reset switch and it starts normally (shut-down is normal). Any comments?

A7V, Tbird 750 @ 900 stable
128 MB NEC PC-133
Voodoo3-3500
SBLive Platinum
SmartStream PCI DSL modem
13GB & 5GB IDE, IDE CD-ROM
Win98SE
 

paulip88

Senior member
Aug 15, 2000
908
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The additional voltage is a known issue. This is why it does not do a cold boot. It detects the voltage out of spec and returnsa hardware error, which prevents the boot sequence from starting.

Why this does not happen on a cold boot or why it no longer happens on my board, I don't know.

Also, have you tried manually setting the voltage to 1.85/1.9v and OCing it from there? Auto voltage means default voltage. If you add more you may be able to get more. Not that 900 is bad. Sure beats me.
 

KurtD

Member
Aug 17, 2000
107
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That explains it - sort of - thanks! This can be one mysterious piece of hardware. Regarding setting the voltage higher, I have a retail CPU/Fan. At 900 it runs between 43 and 50 depending on load. I don't see the need to spend $ on a fan for marginal (further) performance increases. I'm happy with 20% more than I paid for!

Regards,
Kurt
 

Penalty

Member
Oct 10, 1999
96
0
61
If, by power up, you mean power to the case, than the system is working properly. When an ATX case is powered up, power goes to the Mobo and the fans come on for a couple of seconds. This does not boot the machine. To boot the system, you are suppose to use the front power button.
 

daveshel

Diamond Member
Oct 10, 1999
5,453
2
81
This is the most difficult board I've ever had, and I've had a lot of boards. (This is even worse than an early VA-503+!) It is driving me crazy with inconsistent errors. Most of the time my 750 won't even POST at anything but 750 with automatic settings, and once I had windows installed I started getting registry errors and had to start over. It seems stable again, but I haven't added all my PCI cards (the first time it was fine with a modem and sound card and the problems started when I added the NIC).