MP 1,1-5,1 Overclocking the cMP 4,1 and 5,1 to 4.25Ghz

[handheldgames]

Just to clear this up. In Windows, with an Intel 990x Extreme CPU and the Intel Extreme Tuning utility, the cMP 4,1 and 5,1 can be overclocked by increasing the CPU multipliers based on how many threads are running.

By raising the multiplier for Single Core operations to from 28x to 31x, I've essentially boosted single core performance from a max of 3.72Ghz to a max frequency of 4.25 Ghz. Multi-core performance was also increased from 3.59Ghz to 3.72Ghz.

3.86 Ghz Geekbench results
3.99 Ghz Geekbench results
4.25 Ghz Geekbench results

 

[Flint Ironstag]

Windows 8? Why?

 

[h9826790]

Just to clear this up. In Windows, with an Intel 990x Extreme CPU and the Intel Extreme Tuning utility, the cMP 4,1 and 5,1 can be overclocked by increasing the CPU multipliers based on how many threads are running.

By raising the multiplier for Single Core operations to from 28x to 31x, I've essentially boosted single core performance from a max of 3.72Ghz to a max frequency of 4.25 Ghz. Multi-core performance was also increased from 3.59Ghz to 3.72Ghz.

3.86 Ghz Geekbench results
3.99 Ghz Geekbench results
4.25 Ghz Geekbench results

View attachment 1489332

View attachment 1489330

I did that before on my 5,1 with W3690, but as you can see from your own test, single thread performance only improve a little bit, and multi thread performance has no improvement practically.

The theory was the VRM is limiting (CPU can't draw more to perform better).

Windows 8? Why?

Only Windows has software can do that. Test shows the overclock can stay if we warm reboot back to macOS.

 

[handheldgames]

I did that before on my 5,1 with W3690, but as you can see from your own test, single thread performance only improve a little bit, and multi thread performance has no improvement practically.

The theory was the VRM is limiting (CPU can't draw more to perform better).


Only Windows has software can do that. Test shows the overclock can stay if we warm reboot back to macOS.

I've been happy with multi-core performance and was trying to boost the CPU where it's limited.It just shows that increasing Mhz doesn't go to far. It's a fun exercise either way.

I may have to see where the ceiling is before the OS blue screens and restarts. Further gains are held back by a lack of voltage control. At least multipliers are some kind of option.

Too bad we never found out how to modify the multiplier in OSX/MacOS...

Windows 8? Why?

Windows 8 is the last version of Windows with Security updates that can still run Windows Media Center with Cable Card tuner support. It runs great on a 4,1's x58 based platform with 48GB of ECC Server ram.

 

[stockholm80]

Does this cause the system clock go a little faster?

 

[h9826790]

Does this cause the system clock go a little faster?

no