My Llano Overclock

[podspi]

What does that program do differently from CPU-Z to get the correct clockspeed?

And it's great to see people finally running these chips through their paces... Can't wait to see the BE Llanos, if they ever materialize...

 

[formulav8]

What does that program do differently from CPU-Z to get the correct clockspeed?

The program reads the RDTSC timestamp value from a register in the cpu. Everytime the cpu completes a clock cycle the RDTSC register increments by 1. So then all you have to calculate the clockspeed is get the timestamp value before a 1 second pause and then get the timestamp value After the 1 second pause. So when you subtract the two values the result is the processor clockspeed. 🙂

CPUz does it differently. It can detect the multiplyer and external bus speed. Maybe through SMBus data. RDTSC can't do that.

 

[podspi]

The program reads the RDTSC timestamp value from a register in the cpu. Everytime the cpu completes a clock cycle the RDTSC register increments by 1. So then all you have to calculate the clockspeed is get the timestamp value before a 1 second pause and then get the timestamp value After the 1 second pause. So when you subtract the two values the result is the processor clockspeed. 🙂

CPUz does it differently. It can detect the multiplyer and external bus speed. Maybe through SMBus data. RDTSC can't do that.

Very interesting, thanks :biggrin: So it should completely bypass the multiplier misreporting issue, then. :thumbsup:

 

[wirednuts]

i should just part out both my htpc and my desktop and build a new Llano htpc gaming rig. i really dont want to give up my desktop though, when i need to get a lot of work done there is nothing faster.

 

[blckgrffn]

Richie, did you have to run in IDE mode to get the bus that high? Disable QnQ or anything?

I am interested in what kind of clock speeds are achievable without sacrificing other functionality... particularly AHCI for our nice SSD drives 😉

Thanks for sharing your results!

 

[Rvenger]

Ok I reset cmos and reflashed the bios just to see if I had a bad flash and still same results. At stock speeds Im getting 28s Super Pi. It seems some kind of automatic voltage adjustments are occuring, even when all power managment features are disabled. I honestly have no idea whats going on with it, but I do agree the benchmarks are seriously sucking.

I wonder if the TDP cap is throttling the performance once you reach over the 100watt TDP. Those results should be much better. Did you try running Super PI at lower clock speeds (like 3.6ghz) to see if the numbers were the same?

 

[ItsAlive]

I wonder if the TDP cap is throttling the performance once you reach over the 100watt TDP. Those results should be much better. Did you try running Super PI at lower clock speeds (like 3.6ghz) to see if the numbers were the same?

It seemed even though bios showed the settings correctly, that it wasnt actually setting them or they weren't taking hold. At stock I got 28s in Super Pi and with the overclock to 4.2Ghz it dropped to 24s, but in bios it would show the default FSB set to 110 which seemed like it was auto overclocking the FSB. If I went any higher than 110 it seemed to have no effect on Super Pi even tho the bios said it was running at 4.2Ghz. I flashed bios with the EfiFlash tool on the MSI website so I dont think it was a bad flash or anything.

It's possible the TDP cap was throttling it down. I have since RMA'd the board and will try again with a new one soon as I get it back.

 

[Rvenger]

This guy seems to have 16 seconds on his SuperPI. I am just trying to get him to confirm with a screenshot. Maybe the TDP cap doesn't apply and maybe you just had a flaky board.

http://forums.anandtech.com/showthread.php?t=2198692&page=3

 

[Arkadrel]

This guy seems to have 16 seconds on his SuperPI. I am just trying to get him to confirm with a screenshot. Maybe the TDP cap doesn't apply and maybe you just had a flaky board.

http://forums.anandtech.com/showthread.php?t=2198692&page=3

He did post one, if you check the thread.
I ll repost it here for you: (1M at 16secounds)

@ItsAlive

Multiplier overclocking doesnt work with Llano's (your not being powercapped).

Which means your stuck with whatever your highest multipler for that cpu is.
If its 29 and your running 110 fsb, even if you plut multipler to 39... its still only running 3.1ghz
(its just showing 4.2 in windows).

In short..... you need to run ~27 multipler x ~160mhz fsb = 4.3ghz or so.

Thats how you get less 16sec in SuperPi.
(@Rast has his running 4.3ghz, and its giveing the Phenom II x4 a run for their money, in performance)

*Note: Crazy chinese guys have gotten around 5ghz with Llanos.

 

[ItsAlive]

If you check the OP I was using 164 and 169 FSB, I never went over 26 on the multi. Super Pi still only got to 24s even at 4.2Ghz with the FSB overclock. Im pretty sure it was the board, so as soon as I get the replacement I'll try her again 🙂