Why am I getting higher clocks with Twin Turbo off?

When benching with TT off I get 1.8Ghz. When its on i only get up to 1.7ghz.

I thought TT was supposed to increase cpu performance?

 

TT OCs the base clocks, but I think it bumps the VCore too, which causes more heat and forces Turbo boost to use less multipliers. I noticed this myself, and if you bump the BCLK via SetFSB it doesnt seem to effect the 720qm as negatively. When I was playing with SetFSB, I got up to 1.93ghz on 8 thread tests but it wasn't entirely stable.

 

There is a timing issue in windows 7 when you overclock the BCLK using TT or SetFSB. This causes the CPU not to turbo which in turn leads to lower clocks with TT on. There is a simple command line fix for that.

http://forum.notebookreview.com/gam...must-read-setfsb-o-c-game-problems-fixed.html

 

Thanks for link but I already knew about the timing prob when reading about TrottleStop. Ive did the fix weeks ago.

Still, I get more GHz with Twinturbo off....why?

 

Bluefalcon13 summed it up. Intel's Turbo boost is based on power draw, heat, and CPU load. If the BCLK is pushed up, which is what the button does, it causes more power consumption and therefore more heat. Two of the three factors that limit boosting are now artificially increased. That means that Intel's Turbo Boost algorithm will always select lower multipliers so you will see the CPU actually running slower.

In a single threaded application, you may see some performance increase with Asus' Turbo function since the increased draw won't be enough to limit multipliers and you can get at or near max clock as long as the other cores aren't used. If you have multithreaded processes running then the Asus Turbo function will pretty much always cause you to run at lower multipliers.

What I'm trying to say is that Asus Turbo is useless. If you want to overclock you will have better results with SetFSB. Just pushing the bus speed up alone doesn't really buy you anything because it negatively affects the CPU's own multiplier selection algorithm.

 

thank u Jody.

Makes sense now.

 

You are limited by power consumption i would say. Some 720/740qm will turbo with TT on, others won't. to get to throttling CPu temps in a G73, it will be dust, degraded TIM or a large OC on the CPU

 

You are welcome. Glad to help. We beat that issue to death when these laptops came out at the beginning of last year. We were getting a lot of confusing benchmarks with it.