On 28/11/2011 9:12 PM, rms wrote:
Just to give you a data point on overclocking via the bios (which I
recommend vs some windows utility), here are my overclocked settings on
a 1090T x6, on a 890GX motherboard, which it's been at for over a year
now. I used the same settings on my x4 cpu previously.
x17 multiplier = 4080mhz
x11 northbridge mult
x10 HT mult
memory x6.66 mult at 8-8-8-24 1T (corsair 1600mhz dominators)
cpu core volts 1.475v, associated chipset voltages raised also.
So you've overclocked your FSB too? Why would you do that, rather than
with multiplier alone? I assume that the 1090T is a Black Edition, I've
never heard of another kind of 1090T. Doesn't pushing the FSB affect the
stability of other components beside the CPU?
The 11x northbridge multiplier, is that the internal CPU northbridge?
This is a quite high core voltage, and you must stay well below this in
a stock heatsink system. Mine is a highend Noctua NH-D14 with 2
higherspeed fans on it, but still air-cooled.
The AMD site lists a voltage range of 1.125-1.40V for the 1090T
. How high can you push the voltage? How high can
you push the speed using just the design-spec voltage? Do you absolutely
need to go above spec to get to 4GHz?
The core & northbridge voltage (within bounds of course) is the primary
determinant of how far the cpu itself can oc, and when you raise them
temperatures go up. You *must* closely monitor temperatures when doing
stability testing, using a motherboard utility. Keep both cpu & system
temps below a max-stressed *peak* of around 55C. Your bios should have a
'Health' menu where you can force shutdown at a given temp; set this to
about 60C. When testing, if you notice temps still rising at the end of
the test run, back off the voltages a notch and set your sights lower.
This is especially important when gaming for long periods, as the
videocard temperature will rise dramatically as well as the cpu.
I've found that the Turbo Core mode stops working once I've gone over
3.6GHz. Not a huge deal, since Turbo Core is only 3.7GHz. But I've also
tried overclocking the Turbo Core to 3.8GHz, but it simply doesn't allow
Turbo beyond 3.6. This might be an internally set threshold in the CPU
that is beyond our control.
Overclocking SOP is to set fsb & mult as high as possible for a given
core voltage, while keeping the memory within it's stated specs by
adjusting the memory mult & fsb, then run Prime95 on all cores until it
fails or gets too hot. If it gets too hot you must decrease voltages or
increase cooling. If it fails you can bump voltages or change clock
settings. Which clock settings to change is the fun part
I've noticed you're pushing your RAM heavily too, is Prime95 a good
stability test for RAM too, or just CPU? The AOD's stability test is
pretty good for CPU stability testing, pushes all cores heavily, but I'm
not sure if it is a test of RAM stability though.
BTW, you should verify that Windows sees all 6 cores by entering Task
Manager, Performance tab, and check that it shows 6 cpu graphs. If it
does not, there's a simple procedure to fix that.
I've got an utility called Core Temp that shows the state of all cores
continously through a Windows 7 desktop gadget.