I seek advice on the final stages of tweaking required to reach 4GHz
stable on my new i7 860 build. It's fine at 3969 (189x21), but not
quite right at 3990 or 4011, ie. the system boots ok, I can run things
like Firefox & 3DMark06, but it doesn't pass Prime95 or LinX. Note that
using a 20X multiplier didn't work so well, though as I type I'm trying
again (currently at 189x20 & climbing).
System spec:
Centurion Plus 534 case, Scythe SFF21F intake/exhaust
Thermaltake Toughpower 750W PSU
Asrock P55 Deluxe mbd
Core i7 860 (FPO/Batch L935B730)
Thermalright U120E Rev B (with AS5), Scythe Kaze-Jyuni 1900rpm fan (#1)
GSkill Ripjaw DDR3/2000 4GB kit (2 x 2GB, normally 9-9-9-27 @ 1.6V)
ASUS 8800GT 512MB (Glaciator) PCIe gfx
WD VR 10K SATA system disk, 1TB Samsung Spinpoint F3 data
LG 22X DVDRW
Antec Spot Cooler (for the RAM, just in case)
Win XP Pro SP3, apup/Autopatcher, all the latest drivers, etc.
http://service.futuremark.com/compare?3dm06=13967078
#1: The 1900rpm gave temps 3C lower compared to using an SFF21F
1600rpm, though the Kaze is definitely a fair bit louder.
BIOS Settings:
BIOS Revision: 2.00
Bclk: 189
PCIe: 100
Spread Spectrum: Disabled
XMP Setting: Profile 1 (DDR3/2000, 9-9-9-27 @ 1.60V)
CPU Ratio: 21
QPI Link: 6.048GT/sec (Options: 6.080 or 6.840)
VDrop: Disabled
CPU Voltage: 1.38125
DRAM Voltage: 1.629
VTT: 1.309
PCH: 1.086
CPU PLL: 1.895
HT: Enabled
Speedstep: Disabled
C-States: Disabled
DRAM Timings: Manually set to 10-10-10-29, 2T, all others Auto.
Real Temp results:
Idle: 34, 33, 35, 32
Load:
Prime95: 67,70,66,70
LinX: 75,79,74,79
So, anyone have some suggestions as to the best way to reach 4GHz? Atm
I'm not sure whether I have the voltages particularly balanced - do
they look mismatched in any way? When trying it at 190x21 or 191x21,
what should I be changing first to achieve stability? Or even just some
recommendations for making the 189x21 setting run better? Perhaps I've
been increasing core voltage when it should be VTT I should be boosting?
What about the RAM timings?
I didn't want to proceed with further core voltage increases until I'd
heard some opinions. I've done a moderate amount of overclocking in the
past, but am certainly no expert. I know least about RAM timing issues,
though I did discover that switching from 9-9-9-27 all-Auto to
10-10-10-29 did help at one point.
Also, watching the results in RealTemp as tests crunch away, I notice
there seems to be a consistent inter-core temperature difference of
about 3/-1/3, ie. if the 1st core temp is X, then the other three temps
will normally be: X+3, X-1, X+3. Should I infer anything from this? I
was wondering if it implies the HS isn't attached evenly. I used AS5,
but I could redo the setup using Thermalright's own supplied paste, or
maybe AS5 is fine and I just didn't apply it correctly.
I've tried to find some examples other people have posted around, but
it's not easy to locate such info as most users are posting results for
i5 750s.
Anyway, my goal is 4GHz, ie. either 200x20 or 191x21. I would very much
welcome ideas/suggestions.
Note that all tests so far have been conducted with the system lying
flat and case panel removed (this pic taken before the Spot Cooler was
added):
http://www.sgidepot.co.uk/misc/i7working.jpg
Thus, the intake/exhaust fans shouldn't be a factor atm. Once I reach
4GHz stable and fit the panel, if things do get too warm then I have
two more 1900rpm Kaze fans I can use, plus some fan controllers to
perhaps pull them back a bit if the noise is too much.
Cheers!
Ian.