Help OC'ing A64 3000+ Winchester on VNF4 Mobo (Voltages??)

[MajorPayne]

I have one of the new Chaintech VNF4 Ultra motherboards, running an A64 3000+ winchester core. I have been able to get it to clock up to 240 HTT in BIOS (where others have reported being unable to pass 220 with this board) running the processor at 1.5 V, (where it runs at 21-26 degrees C depending on the load, so I know I have room to go further!) and the memory (2x 512 of Kingston hyperX 3200) at 1.7V. I had to lower the HTT multi to 4x (from 5x) to get it to OC, but this is expected. I also set the RAM speed to 166 (down from 200 by default), which at a 240 HTT makes the ram speed 406 MHZ.

The system is VERY stable at this overclock (runs at 2.16 GHZ up from 1.8 stock), but I KNOW it can be pushed further than this. Every OC I try above 240 results in the motherboard rebooting to "safe settings" where the CPU is clocked down until I go into BIOS and set the OC back. I have tried lowering the HTT multi to 3 AND then to 2, and I dropped RAM speed to 133 and relaxed the timings a LOT, but still cannot get one whit past the 240 mark. I suspect that my CPU voltage needs to go higher, in order to get a better OC. I have tried upping the RAM to 1.8V, but I still could not get any higher.

Which brings us to my questions. For those who have overclocked an A64 3000+ winchester (or any other winchester), did you need to raise your CPU voltage past 1.5, and if so, how far up did you/can you safely go? Any advice or examples from a working overclock would be appreciated. Ordinarily I would just run the sucker up, but I used up all of my wife's "goodwill towards technology upgrades" just getting her to let me buy the new processor, motherboard, and graphics card (a 6600GT). If I fry this processor, I will be without a new one until I can weasel yet more upgrades out of her!

By the way, I MAY have cool-n-quiet enabled (I think I do, because I think it is defaulted to ON on this board), and I have heard that this can limit your overclocking ability as well. Any thoughts on this too?

 

[superkdogg]

I have that chip and I'm @ 300x9 with 1.475 vCore. Look to your motherboard settings, especially regarding the AGP/PCI lock. 1.5 vCore should get you more than where you're at with that chip. Try actually dialing down the vCore-I bet you could get your current OC @ stock (maybe- some others have gotten all the way to 2.5-6 w/1.4). It kinda sounds like I'm being a braggart or a d!ck, but I'm not. I'm just telling you that there' more potential in there and you need to find it.

 

[MajorPayne]

Originally posted by: superkdogg
I have that chip and I'm @ 300x9 with 1.475 vCore. Look to your motherboard settings, especially regarding the AGP/PCI lock. 1.5 vCore should get you more than where you're at with that chip. Try actually dialing down the vCore-I bet you could get your current OC @ stock (maybe- some others have gotten all the way to 2.5-6 w/1.4). It kinda sounds like I'm being a braggart or a d!ck, but I'm not. I'm just telling you that there' more potential in there and you need to find it.

No you are not being rude, I understood what you are saying. I have tried many things to get this mobo past 240, and it just does not happen. The PCI lock on this board is automatic (it comes on when you OC the HTT over 203). There is no APG lock, since this is a PCI-E board, but it does have a PCI-E lock, and it allows you to raise or lower the PCI-E bus speed independently as well. Both PCI-E and PCI locks are on by default, with no way to turn them off. I also DID go ahead and try upping the Vcore last night, I went as far as 1.7 (for a short time), with 1.8 on my RAM, but I still cannot get it to even post past 240 (even just at 242) no matter what I do. I tried an HTT multi as low as 2x, lowered my RAM speed, raised the timings on my ram to 4-4-4-11, and tried basically everything I could think of. I think 240 is all I will get out of this BIOS. Hopefully Chaintech will release another BIOS with better OC potential, since this BIOS is the first one for this board, and I know that other people with this board could not even get past 220, so I am not too bummed.

 

[superkdogg]

Sorry, I didn't realize it was PCI-E. Anyhow, it could be a bios issue. My main point is that I doubt you're CPU limited. Many people have gotten quite good OC's out of the Winchesters with low-ish voltages. Good luck to you and don't give up.

 

[MajorPayne]

Originally posted by: superkdogg
Sorry, I didn't realize it was PCI-E. Anyhow, it could be a bios issue. My main point is that I doubt you're CPU limited. Many people have gotten quite good OC's out of the Winchesters with low-ish voltages. Good luck to you and don't give up.

Yeah, I figure this for a BIOS issue myself. I originally started at 1.4V for the CPU (stock), and then tried upping it to see if it would help. It DID help with stability of the OC -- it is rock stable now -- but it still will not let me pass 240HTT. I upped voltage as far as 1.7 on the processor and RAM up to 2.8, disabled my excellent compatriot-2-quiet, and even tried lowering my HTT multi to 2x, but still cannot get this board to go above 240HTT. Even 242 causes it to go to "safe mode" with the processor underclocked.

The good news is that at 240HTT it is rock stable, and I have it this way with 4 (!) sticks of 512MD Kingston HyperX DDR 3200 running at 406MHZ, with 2-2-2 timings (I also tried going back to 2 sticks at loose timings, but no luck there either). I have run 4 loops of memtest without errors, and ran Prime95 all night long with no errors. Since most report not being able to get past 220 stable with this board, I am definitely happy at 240, but I feel I could go higher with a better BIOS.

This board's BIOS DOES offer some unusual options that I have not seen before though. In the Advanced Chipset section, after the HTT multiplier option, there are options to set the HTT Width (16 up, 16 down default, then 8x8, 4x4, etc), and something called Err94 Eng (default is auto, can be set to on or off also). In the voltage section, there is an option to set the chipSET voltage (in addition to chip and RAM voltage) -- I suppose that it is possible that the voltage for the Chipset is holding me back in my overclocking, but I am leery of upping this, since this board's chipset has passive cooling only! If anyone can shed some light on the above BIOS options (what they do, what the safe settings may be, and/or if you think they may be the key to overclocking this board further, please let me know!

 

[MajorPayne]

By the way, one thing I heard mentioned earlier in Anandtech's review of the SIS 755FX Chipset for the A64 is that the that board (not the VNF4, which as far as reviewers etc. are concerned does not exist!) has a poor stock clock generator built in, which will not let you past an effective speed of 233 (even though it appears to pass this, the CPU speed does not really change past this point). I am starting to wonder if this board has a similar situation -- I do not know much about motherboard clock generators, so I cannot say for sure, but it definitely seems that some kind of artificial limitation is preventing passing the 240HTT point. Hopefully this is not the case tho, since the clock generator is a physical part (that cannot be changed by a BIOS update) and this would relegate us permanently to the 240 point. Does anyone know if the clock generator on this motherboard may be holding back my overclock?