hi dudes,

thanks for reading my post. Ok first up this is my initial OC settings:

Bus:300
Mulitiplier:8x
Divider:266mhz
HTT:3x
V Core: stock
total: 2.4ghz @ DDR400 HTT:900

with the above settings my system runs fine as my Rams are still within Spec not Exceeding DDR400.

However when i try to OC my system to 2.7ghz the system refuses to start even when i change my Ram Dividers to DDR200 which also equals to DDR400

Bus:300
Multiplier:9x
Divider:200mhz
HTT:3x
V Vore: 1.35 all the way to 1.4 still wont start
Total: 2.7ghz @ DDR400 HTT:900

is there any reason why my system wont start @ 2.7ghz? could it be the Rams that are holding me back? but even so, with the Dividers there they are still within the DDR400 specs no reason for it not to start

Becos i m using Corsair 3200XL LED i can see my Rams @ 100mhz when the system refuses to start.
Temps are really fine low to mid 30s when my system is idling @ 2.4ghz high 40s to low 50s on load

thanks for any advice/info

Have you tried increasing the Vcore?
How about chipset/NB voltages? Increased those yet?

Hi pcmoddingmy,

thanks for reading my post, hav just tried and still it wont start. In fact instead of going for such a big jump from 2.4ghz to 2.7ghz i just changed my multiplier to 8.5x meaning <300x8.5=2550> an increase of just 150mhz, the system still refuses to start. Even when my Rams voltages to 2.70, chipset voltage maxed out to 1.6 for A8N-SLI Premium, Vcore all the way up to 1.42. It still refuses to start @ 2550mhz

Other than that seen another BIOS option is HT voltage which i didnt attempt to change.

ok ignore my sig, previously i was running SLI with the 700w PSu now that i m in single card and using a Antec Neo Power 480w do u think its gotta b the PSU that cant supply enough juice to supplement the additional overclock?
What do u think ? time for a new mobo like DFI Lan party and a PSU ?

Thanks

Firstyly, pls avoid using the x.5 multipliers.
If you have troubles going for 2.7ghz, try 2.5ghz and 2.6ghz.
Maybe you CPU needs to be burnt in to reach 2.7ghz.

1.42Vcore is almost stock vcore. Are you sure thats the max for your mobo? How about VID? You should be able to get atleast 1.7Vcore from your mobo...

ok thanks again for your prompt response, really appreciate it , hmm i was told frm some forums to avoid pushing vcore to not more than 1.45 as it shortens or kill the cpu. think i would like to believe that i really need to burn in the cpu in order for it to reach that sort of speed.

As im seeing lots of opteron 165s cruising @ 2.7ghz easy 1.4-1.5volt

finding it kind of weird that its not going pass 2.4ghz

to my knowledge overclocking any procs is simple as in with increasing bus speed and voltage, increasing chipset voltages and Ram voltages only helps to fine tune the system to maintain stability. In this case, doesnt seem like my current rams and or chipset voltages are the ones holding me back on the overclock ?

Thanks again for your response

Well, I think its safe to push the vcore up to 1.6V and it won't shorten or kill the cpu, provided if you have a better cooling. Your CPU will last longer if it runs cooler when overclocked. Maybe you can try setting it to 1.5V just to see if you can reach 2.7ghz...

hi There pcmoddingmy,

I've manage to start my PC @ 2.7ghz !!! i went straight for 1.5volt in BIOS which is the highest for the A8N-SLI Premium dont have anything after that... my system is running pretty cool as well which is good news! 35 DegreeC @ idle for the moment have yet to test whats it like on load... Which is what i m gonna do over the next few days stability test

Its pretty sad to see a A8N-SLI premium having 1.5volts as the max vcore hopefully Asus would come out with a newer BIOS with slightly more Vcore volts. Any further would mean that i have to purchase a DFI Lan Party.

Many thanks for your advice/info

Hello bulldog,

Looks like you need to update your BIOS. Here's a screenshot of the A8N-SLI Deluxe's BIOS page. Looks like it can go up to 1.65V easily...but you'll only need 1.6V

Anyways, remember that overclocking voids your warranty and we take no responsibility for the damage that might occur.

Btw, thread moved to Overclocker's Palace.

Bro,
If your Vcore is really limited to 1.5V, trying using this Windows based overclocking program Clockge for NF4.

Unzip the file and run CG-NVNF4.exe. Should be something like this:



Click the K8 FID/VID tab.
In the Voltage Control section, slowly increase the New Value.
Click "Apply VID" and observe the Vcore in MBM/Speedfan/AiBooster.
If you have set the BIOS vcore to maximum value, please becareful when increasing the VID in Clockgen.

Let us know if this trick works for you.
Btw, you can also use this program to increase the HTT/FSB... but watchout for the memory clock.

Btw, i've heard of certain cases where the opteron 165/170 can't boot at 1.55v and higher at 2.7GHz, but can at 1.45v. I know it may sound wierd, but you may want to keep that in mind as well although in most cases, higher Vcore/VID allows higher overclocks.

Hi there, thanks for the reply

yeah fully understand overclocking voids warranty of any sort no worries dude

thats the reason why i bought an opteron. Anyways realised that my BIOS has only the option of up to 1.5vcore is becos i m using the latest BETA bios hence the limit to the Vcore.

Currently i m about to update to the latest non-Beta Bios version which is slightly older that the current beta bios that im using by a few months.

Thanks for providing the link for the windows based overclocking tool, but im going for the old school method of overclocking the BIOS.

with regards to Vcore the max im willing to go would be about 1.55-1.6 @2.7ghz as i my system starts fine @2.7ghz 1.50vcore but is not stable when im running games. It looks like my CPU needs a tad more volts so im gonna see how it goes.

will keep u updated with my progress

Thanks for your reply so far u guys have been a great help

Hi guys im back and this time geared with a new Mobo for my overclock target @ 2.7ghz stable.

Firstly, some reasons on buying a new mobo. Have done some research and found the DFI-Lan Party UT SLI-DR expert board to be the best overclockers board around for now as it really provides vcore all the way up to 2.1vcore !!! more Ram Dividers as compared to my Previous Asus A8N-SLI Premium mobo. Much more Ram settings, individual overclock profiles etc...

Anyways with this new board i still managed to get my system to 2.7ghz @ 1.525 however the system is not stable as it only primes for about 4mins and fails the Prime test. Then i decided to prush my vcore upto 1.55v and Prime95 manged a better 21minutes before failing!!

What are the reasons for failing Prime95 it really seems obvious that with a higher Vcore from 1.525 to 1.55v i was able to prime longer before failing the test @ 21minutes

So to conclude does this mean that for my system to run @ 2.7ghz i need to push it to 1.5725 up to 1.6v or until a voltage when Prime95 doesnt fail just to conclude that my sytem has hit its limit?

Thanks for any responses

Managed to get Prime stable @ 1.62 vcore Temps ok abt mid 30s on idle, mid40s on load

Hello there... nice to hear from you back.
As for overclocking Optys, get them on water if you want to run low Vcore.
I've seen some doing 3GHz at stock Vcore.. on water of cause.
But sometimes it all boils down to the chip.
I have an Opty 144 and does 2.9GHz at 1.58V.. Super PI 32M stable but errors out in Prime95 within seconds. It was Prime95 stable at 2.7GHz 1.4V but that was with water.

Btw, are you sure that the memory isn't the culprit? Are you running em' on dividers? Whats the highest your Xpert could do? If thats the mem your using..

Yeah I was wondering if it could be the memory thats giving all this headache, since i managed to prime95 stable at 1.62vcore i was doing it on some ram dividiers cant remember what they were but my RAMs wont running @ DDR400 but DDR360 instead. Do you think a pair of Good OCZ DDR500 would help? So i can bring my vcore down abit more???

I am really thinking hard as to why do i need 1.62vcore to hit 2.7ghz stable? i am looking around in some DFI forums that many opty 165 hitting 2.7ghz @ 1.5+ vcore. Some are suggesting that there are many settings in the DFI Genie BIOS that i have not adjusted that causing me to require high vcore as a result

Thanks again for any response

If you were to run your Opty at 2.7GHz, you need to get the HTT at 300MHz, right?
If you were using DDR360 at 300MHz HTT, your RAM frequency should be 270MHz. The question is, will your Xpert run stable at 270MHz in whatever timing?

I'll say, drop the CPU multiplier to 8x and see if you can Prime with your RAMs at 270MHz or 300HTT. Then once you have found your max stable speed for your RAM, you can start focusing on the proc.

You can also do the easier way our which is to drop the DRAM to DDR333 or lower but some CPU+mobo+RAM combination are known to have issues running memory dividers.

Hi Pcmoddingmy,

Reckon that my vcore is way too high i have decided to back off my vcore and lowered it to 1.550 currently running 2.6ghz instead with my Rams @ approx 378mhz and seems to be Priming dual instances fine and im getting much better temps.

Next Step hopefully will be for a set of 2x1Gb G-skill Rams and a DangerDan watercooling set up and will try to hit for 2.7-2.8ghz although my ideal target is 3ghz on water but unfortunately my Stepping doesnt seem to allow

will keep u posted on how my next upgrade be hopefully able get some pics up

Many Thanks for sharing your views and advice