Overclocking: Asus P5LD2 SE, Core 2 Duo 2.1GHz (E6400)
From:
"andrew cooke" <andrew@...>
Date:
Sun, 11 Mar 2007 21:57:00 -0400 (CLT)
Below is a record of my experiments. There may be some errors, as the
data were transcribed from rough notes on scraps of paper. The basic
conclusions are:
- fine details don't matter too much as there are so many things to vary
(in other words, there's more than one way to hit the same bottleneck)
- the board is very nice at "helping" with various automatic choices, but
that also becomes a limiting factor (see below)
- using stock components it's possible to get a 25% performance gain.
- none of the above changed voltages (except for any "automatic"
adjustments) and there seems to be very little risk involved
(only once did I have to hard reset the motherboard).
- typically the board either works, or fails to boot. Very few
settings gave unstable behaviour later.
- top configurations are:
fCPU fClock t speed
2.77GHz 346MHz DDR922 5-2-2-18 0.78 +28%
2.66GHz 333MHz DDR888 4-4-4-11 0.79, 0.81 +23-27%
2.77GHz 346MHz DDR692 4-4-4-11 0.80, 0.80 +25%
2.77GHz 346MHz DDR692 5-2-2-18 0.83 +20%
2.13GHz 266MHz DDR712 4-4-4-11 1.00 (reference)
where "t" is normalised time relative to the base config and
"speed" is the relative % speed increase (100 * (1/t - 1))
The values given for frequency and memory settings are taken from
Memtest86+, v1.7. They do not always agree with the BIOS settings (see
details below, where BIOS settings are given on first line).
The details below show that it is difficult to reach the settings achieved
directly. Instead the boards "automatic" values need to be used -
entering direct values typically gives board lockups. This may be because
using automatic settings also modifies voltages (which I otherwise left
alone).
I don't really understand memory timings, but 5-2-2-18 does look odd. I
will probably go with 2.66GHz 333MHz DDR888 because it gives good
performance with less worry about CPU heating, and avoids the odd memory
values. I have run that setting overnight on Memtest with no errors.
Note the strange memory multiplier (which fits those "4" values into "3").
The FSB is then 1665MHz.
Andrew
overclocking notes
090307 - all standard voltages
a 3.00GHz 375MHz DDR750 4-4-4-11 fail
b 3.00GHz 375MHz DDR563 4-4-4-11 fail
c 2.80GHz 350MHz DDR933* 4-4-4-11 fail
d 2.77GHz 346MHz DDR923* 4-4-4-11 fail
e 2.77GHz 30% Auto 4-4-4-11 kernel 13m31s
346MHz DDR692 4-4-4-11
f 2.77GHz 30% DDR922* Auto overlooked candidate?
346MHz DDR922* 5-2-2-18 (see below)
g 2.77GHz 30% Auto Auto kernel 14m02s
346MHz DDR692 5-2-2-18
h 2.66GHz 333MHz DDR888* 4-4-4-11 fail
i 2.66GHz 333MHz DDR666 4-4-4-11 kernel 13m24s
333MHz DDR888* 4-4-4-11 (compare w above!)
j 2.66GHz 333MHz DDR1110 Auto? fail
k ? 888/DDR667 Auto fail
l 2.33GHz 10% Auto Auto
292MHz DDR584 5-2-2-18
m 2.24GHz 5% Auto Auto
280MHz DDR746* 4-4-4-11
n 2.13GHz Auto Auto Auto kernel 16m53s
266MHz DDR712* 4-4-4-11 mobo default
fastest cpu speed attained was 2.77GHz (e)
fastest 4-4-4-11 memory is DDR888* (i)
5-2-2-18(!) memory doesn't seem that useful (g), but perhaps (f) ok? (i)
was an attempt at a balanced solution - seems good
comparing (e) and (g), 4-4-4-11 v 5-2-2-11 is ~4%
strange bug in (h)/(i) - memtest or mobo wrong?
if memtest correct, (i) and (d) memory limit between DDR888* and DDR923*
otherwise (m) has fast memory
try:
350MHz, DDR750, 4-4-4-11 (pushing i/f)
346MHz, DDR922*, Auto (f)
350MHz, DDR933*, Auto (pushing f)
333MHz, DDR888*, 4-4-4-11, higher V? (retry h)
100307 - all standard voltages except (p)
o 2.80GHz 350MHz DDR700 4-4-4-11 fail
p 2.80GHz 350MHz DDR700 4-4-4-11 fail FSB 1.3V
q 2.66GHz 333MHz DDR888* 4-4-4-11 fail (confirm above)
r 2.66GHz 333MHz DDR833! 4-4-4-11 fail
s 2.66GHz 333MHz DDR711! 4-4-4-11 fail
t 2.13GHz 266MHz DDR889! 4-4-4-11 fail
u 2.13GHz 266MHz DDR771! 4-4-4-11 fail
v 2.72GHz 340MHz DDR680 4-4-4-11 new best candidate?
340MHz DDR906 4-4-4-11
w 2.77GHz 346MHz DDR923* 5-5-5-15 fail
x 2.77GHz 346MHz DDR923* 5-2-2-18 fail
y 2.77GHz 30% Auto Auto
346MHz DDR692 5-2-2-18
z 2.77GHz 346MHz Auto Auto
346MHz DDR692 5-2-2-18
- 2.77GHz 346MHz DDR865* Auto fail (hard)
= 2.77GHz 346MHz DDR692 4-4-4-11 fail (in memtest)
_ 2.77GHz 346MHz DDR692 5-2-2-18 fail
f 2.77GHz 346MHz DDR692 Auto previous (f) must have had error
346MHz DDR922* 5-2-2-18
e 2.77GHz 346MHz Auto 4-4-4-11 equivalent to (e above)
346MHz DDR692 4-4-4-11
$ 2.66GHz 333MHz DDR666 Auto doesn't give (i)
333MHz DDR888* 5-2-2-11
so after all that we have three candidates.
all odd - need auto and/or conflict between bios and memtest
e 2.77GHz 346MHz Auto 4-4-4-11
346MHz DDR692 4-4-4-11
f 2.77GHz 346MHz DDR692 Auto
346MHz DDR922* 5-2-2-18
i 2.66GHz 333MHz DDR666 4-4-4-11
333MHz DDR888* 4-4-4-11
note that none can be specified exactly:
= 2.77GHz 346MHz DDR692 4-4-4-11 fail (in memtest)
_ 2.77GHz 346MHz DDR692 5-2-2-18 fail
i is specified exactly, but measures differently
kernel compile times (while rebuilding raid):
e 17m45s (33m/4m)
f 17m20s (31m/3m)
i 18m06s (34m/3m)
n 22m18s (39m/4m)
normalising all results:
f 2.77GHz 346MHz DDR922 5-2-2-18 0.78 +28%
i 2.66GHz 333MHz DDR888 4-4-4-11 0.79, 0.81 +23-27%
e 2.77GHz 346MHz DDR692 4-4-4-11 0.80, 0.80 +25%
g 2.77GHz 346MHz DDR692 5-2-2-18 0.83 +20%
n 2.13GHz 266MHz DDR712 4-4-4-11 1.00
difficult to improve further because nothing fixed exactly.
cannot "push" auto value. don't want to play with voltages.
Slightly Faster
From:
"andrew cooke" <andrew@...>
Date:
Mon, 12 Mar 2007 09:09:25 -0400 (CLT)
After checking out what "safe" voltages might be for memory, I realised
that my mobo (Asus P5LD2 SE) is not at all hard-core, and that its maximum
voltage (2V) is not a problem. Using that, and a CPU voltage of just
1.4125V, I can get to:
fCPU fClock t speed
=======================================================
2.72GZ 343MHz DDR914 4-4-4-11 +24-28%
-------------------------------------------------------
b 2.77GHz 346MHz DDR922 5-2-2-18 0.78 +28%
a 2.66GHz 333MHz DDR888 4-4-4-11 0.79, 0.81 +23-27%
2.77GHz 346MHz DDR692 4-4-4-11 0.80, 0.80 +25%
2.77GHz 346MHz DDR692 5-2-2-18 0.83 +20%
2.13GHz 266MHz DDR712 4-4-4-11 1.00 (reference)
Where the speed is extrapolated from the 2.66GHz config (a).
Looking again at the table above, I am surprised by the performance of the
2.77GHz DDR922 case (b). I have been focusing on the 2.66GHz because (i)
the CPU speed kept low and (ii) it doesn't rely on "auto" settings (apart
from the strange 4:3 difference between specified and actual memory
speed). But this seems to be pretty much the limit. Maybe I should try
extending (b) with the new voltages, as the CPU seems to have a lot more
"headroom" than the memory.
Andrew
3.04GHz, but no Disks
From:
"andrew cooke" <andrew@...>
Date:
Mon, 12 Mar 2007 18:07:34 -0400 (CLT)
Heh. So I tried leaving the memory timings on Auto (ie 5-2-2-18), setting
the memory to 2V, and upping the clock speed. The CPU and memory work
reliably (Memtest passed) at 380MHz (DDR1013!), but the SATA controller
(ICH7) fails to find the disks. Pity... The mobo allows the ICH7 voltage
to be raised slightly, but it made no real difference - the fastest speed
at which the disks are detected is 350. Since I have 4-4-4-11 at 343 it
seems pointless.
Also, losing your disks is not a nice feeling.
In the future, however, I should buy a better mobo. Overclocking was
never my intention before, but now I understand what's happening and it's
clear the mobo is critical.
Andrew
Another 1 percent
From:
"andrew cooke" <andrew@...>
Date:
Mon, 12 Mar 2007 20:57:27 -0400 (CLT)
Hmmm. I tied (e) again (faster CPU at the expense of the 4-3 multiplier
for memory access). And it seems to be a couple of percent faster on the
kernel compile. However, something flakey is happening with the display
as I type this, so I'm going back to the slower version.
Both these are memory at 1.95V:
2.74GHz 343MHz DDR914 4-4-4-11 12m46s
2.84GHz 355MHz DDR710 4-4-4-11 12m27s (video problems)
Higher than 355 again lost the disks...
Andrew
Non-CPU Cooling Helps
From:
"andrew cooke" <andrew@...>
Date:
Fri, 18 Jul 2008 09:13:00 -0400 (CLT)
As part of generally keeping my server cool (it's a packaed case with 6
discs and all PCI slots filled, including an aircooled Graphics card with
a rather large heatsink and th edisk temperatures were getting worryingly
high) I added an extra fan - one of the bigger, quieter ones - on the side
of the case, pulling in air through holes on the case side.
As a consequence, there's extra air flow over the motherboard, including
the heatsink over what I guess is the southbridge(?). Given that the
limits I hit before came from losing the disks rather than CPU overheating
I wondered whether this extra airflow would let me increase the clock
further.
It does - I got to 355 MHz with all other settings on "Auto" (that's
2.88GHz). I've dropped it to 350 and am running with no issues so far
(but don't do many long-term CPU intensive tasks).
Incidentally, I don't lose my SCSI disks (a couple of old disks configured
as RAID1 that hold /var and improve the response of the system
considerably, because the main RAID 5 isn't bothering with basic system
maintenance) which are connected via a PCI SCSI card. So if you don't use
the SATA connections you could go higher...
Andrew
Latest BIOS - No Memroy Remap for P5LD2 SE
From:
"andrew cooke" <andrew@...>
Date:
Mon, 25 Aug 2008 15:19:00 -0400 (CLT)
I just updated my BIOS (v1208) (using CD and FreeDos as described here -
http://forums.whirlpool.net.au/forum-replies-archive.cfm/663321.html ) and
nothing much changed. In particular, I still see no "remap memory" option
that would allow the full 4GB of memory to be used (if you search the web
various people mention this option, but as far as I can tell, it's not
present on the P5LD2 SE model).
Also, in search of a simpler life, I now simply set the board to 30%
overclocking using the "auto" feature, rather than setting clock values
manually. It's very close to the same speed I could get by hand, but a
lot easier.
Andrew
Overclocking Again
From:
"andrew cooke" <andrew@...>
Date:
Tue, 26 Aug 2008 22:07:34 -0400 (CLT)
Looking at this one more time, with the new BIOS (not sure it's changed
anything) and focussing on only the high level settings, I found that:
- 30% faster "automatic" reduces the memory speed from DDR2-533 to
DDR2-400 and runs the CPU at 2.78GHz.
this still gives a 22% speedup (using an arbitrary compile benchmark)
- FSB1333/DDR2-667 "automatic" doesn't seem to do what it says.
CPU runs at 2.68GHz and memory at DDR-4300 according to the initial
boot screen. But that doesn't make sense since the CPU multiplier
is 8 (8x333) which would make the memory DDR2-667 (as set). So maybe
the number reported on the boot screen is wrong in this case?
Anyway, also gives 22% speedup.
- FSB1333/DDR2-834 caused boot to hang, but first reported PC2-5300
(ie DDR2-667). Perhaps again reported wrong?
- Setting both clock speed and memory speed together "manually" at
350MHz (2.8GHz) and DDR2-700 is about as fast as I can get without
hanging. Gives a 30% speedup.
- Finally, at one point (manually setting DDR2-800) I got a black screen
with "WAIT..." in white letters in the middle. No idea what that was
(eventually had to reset mobo by removing battery).
Andrew
New Mobo
From:
"andrew cooke" <andrew@...>
Date:
Wed, 10 Jun 2009 06:21:19 -0400 (CLT)
With a new Motherboard (perhaps not necessary) and cooler (Zalman CNPS9500
AT), and faster RAM (DDR800, critical) I am now running at 3.4GHz,
completely stable. See http://www.acooke.org/cute/Overclocki1.html
With faster memory I think I could go faster still: the current limitation
is memory errors; core temp seems just fine.
Andrew
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