Hi guys.

 

Just by luck I won an auction on a cheap Athlon X4 740 yesterday. Since my 750K is real bad, requires like 1.55 vcore for 4 500 MHz, I'm pondering the thought of using the 740 instead. I've been benching both A10-6700 and 750k on single stage and could run like 140-150 Mhz fsb. No idea whre I'll end up on air for 24/7 use though.

 

Anyone tried say 120 MHz fsb for everyday use? USB3/Pci-e issues?

Epic chip

 

http://valid.canardpc.com/x7vym4

 

To answer my own question - I lost network and audio already at 130 FSB. That's with discrete cards for both, asus dgx pci-e and asus pci-e wifi card. Seems like pci-e frequency is directly tied to fsb on FM2, unlucky! Max stable base clock should be in the whereabouts of 120-125 MHz fsb.

 

I will post some more results with this good chip, 4900 MHz cinebench was easy at 1.475 Vcore (Custom H20 cooling, ambient temp ~20 Celsius.). Pity about the locked multiplier.

On the more expensive boards there are two PLL. One is in the South Bridge and should be used when going over 133 MHz. The max clock for that PLL is around 170 MHz, give or take a couple MHz because of stuff like spread spectrums.

Hi Pieter, thanks for the reply. Doesn't seem like GA-F2A85X-UP4 has this option. I'm a bit surprised, but I just can't see anything like PLL choice in bios (now running F5b).

Hm, if I remember correctly the A85X-UP4 has the two PLLs. Maybe it's not in the BIOS.

 

It's been so long I've run that board. Let me check

Please do I'm forced to run max 119 MHz fsb/pci-e right now, over that my sound card drops out between reboots. It gives me 4180 MHz on the cpu @ 1.25 Vcore. It can do so much more

Checked and confirmed.

 

In order to switch to the SB PLL, you need to boot at >133 MHz. Preferably a bit higher, like 140 MHz, to ensure the PLL is switched.

Yes, you need > 136, then the PLL should be automatically switched.

However, I had problems with dual channel in that case.

Not sure what was the case with blck > 136, but when using the integrated pll, you'd want your SATA controller running in IDE mode.

Thanks guys. But, will this really mean pci-e frequency isn't tied to fsb when I set fsb = 140?

136, 137, 138, 139 and 140 MHz = all will loose audio card after a few minutes. Dammit, haven't seen this stupid bios logic since s478. Hard lock pci-e to fsb seems so pointless.

Hm, Cookie says onboard audio works fine at 140MHz.

 

I'm pretty sure there's a PCIe lock in those PLLs. Doesn't make sense not to have one ...

I'm not using onboard audio, but thanks for mentioning that option. It becomes a trade off here - high clocks OR working audio card, usb3 and wifi

I have 140 FSB on Daily Usage

And my audio, and network working ok

depends, I think, at chipset too (external clock generator etc)