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EmilG
03-07-2008, 08:50 PM
Just putting together my system, it's only running in bios off a floppy to setup the cpu and memory overclocks. I have a strange inconsistency or maybe I'm just not understanding something. When I set a memory multiplier of 3.33 I can run through memtest86+ just fine, when the only change I make is lowering it to 3.2, it won't even boot. I went into the advanced memory settings and set them manually so they would not change automatically but same result.

Any ideas for me to try? This is not a big issue but I'd just like to understand why, I must be missing something.

Q6600 @ 3.0g, 334 x 9
2g Corsair pc8500 5-5-5-15 @ 1112 (3.33)
F7 bios
rev2.0

Thanks

(btw, the board is awesome, incredible value!)

Lsdmeasap
03-08-2008, 12:13 AM
Too tight of subtimings maybe or not enough volts to mch or memory itself. Have you read thru the guide I posted?

If not have a look at that and see if it helps

If that doesnt get you anywhere, copy/paste this back to me with your info +/- any info >>>
Robust Graphics Booster___________ [Auto]
CPU Clock Ratio ____________ [XX]
CPU Host Clock Control_ [Enabled]
CPU Host Frequency (MHz)__________ [266]
PCI Express Frequency (Mhz)_______ [102]
C.I.A. 2__________________________ [Disabled]
System Memory Multiplier (SPD)____ [2.00]
DRAM Timing Selectable_______ SPD __ [Manual]

CAS Latency Time_____________ 5 ____ ?
Dram RAS# to CAS# Delay______ 5 ____ ?
Dram RAS# Precharge Delay_____5 ____?
Precharge Delay (tRAS)________15 ____ ?
ACT to ACT Delay (tRRD)_______4 _____ ?
Rank Write to READ Delay______3 _____ ?
Write to Precharge Delay______6 _____ ?
Refresh to ACT Delay________42 ______ ?
Read to Precharge Delay_______4 _____ ?
Static tRead Value_______________ 1-31
Static tRead Phase Adjust________ 1-31

System Voltage Control____ [Manual]
DDR2 OverVoltage Control__ [+0.300V]
PCI-E OverVoltage Control_ [+0.1V]
FSB OverVoltage Control___ [+0.1V]
(G)MCH OverVoltage Control [+0.1V]
CPU Voltage Control_______ [1.25]

EmilG
03-08-2008, 01:45 AM
Thanks for the reply,

I cruised through your excellent guide, I'll get you specific values by tomorrow.

Like I said though I have values that pass and are stable. I then effectively underclock relative to them and it won't boot?

Thanks again

Lsdmeasap
03-08-2008, 01:53 AM
Ahh well yeah post back when you can.

Underclocking leads to instability then? Hmm maybe you need less volts on something or your underclock settings still need a small adjustment

EmilG
03-08-2008, 04:56 AM
After spending way too much time on the web :) I think I know where the problem is coming from, the strapping settings.

I don't understand how the strapping settings are supposed to be used in the bios. It looks like they are tied to the 4x multiplier, is there a way to get a lower multiplier and force a strapping setting? I'll try when I get home.

Anyway I'm thinking that if I go from 334 to 333 a strapping boundary will be crossed and I'll see what happens then, especially to my memtest86+ memory speed values. What I learned is the Intel defined strapping boundaries are at 266, 333 and 400.

Thanks

Lsdmeasap
03-08-2008, 05:04 AM
Ya you can try that, try 1-3 above or below the strap. Or you can use a lower cpu multiplier such as 8 and use 375 as FSB or use 400 and run at 3.2, whicI believe would be easiest to do, and then you could run at a lower multi. Or just run your ram at tighter timings and run it at 800 1:1 multi. Which in the end with tighter timings and 1:1 could be better/faster anyway

EmilG
03-10-2008, 11:12 AM
Quick report,

It's running very nicely at 334 FSB 3.33 multiplier. I got it run at 3.2 by changing to Turbo vs the Extreme I used for the 3.33.

Since it's running so nice I'm just gonna leave it.

BTW I did try 375 x 8 without any issues but the memory throughput was a bit lower that's why I'm staying at 334.
I also did try 355 and to my surprise it also ran very well, I'll reserve this setting in case I run out of power later on.

Thanks for your help.

EmilG
03-10-2008, 11:15 AM
Another quick question,
do you understand what the multipliers with the strapping values tied to them mean? I thought maybe if I hit the character they showed (~,#,=) it would use the strapping parameters at the multiplier I selected but there was no indication that it did anything.

Thanks again

Lsdmeasap
03-10-2008, 11:48 AM
Well if you do not see the Strapping ~#=+ signs by the values shown then you are not in the strap range, if you do see them you can just select one of the ranges. NO extra key input is needed, and yeah I dont see a improvement or decrease in bandwidth myself either, but I havent done much testing on them as I keep a 1:1 ratio anyway.

Here is a more in depth discussion about strapping>>>

http://www.xtremesystems.org/forums/showthread.php?t=128913
http://www.thetechrepository.com/showthread.php?t=30
http://www.overclock.net/intel-motherboards/145468-intel-overclocking-redefined-interesting-p965-975x.html


Here is P35 straps

FSB Strap to Northbridge
200MHz, 266MHz, & 333MHz

System Memory Multiplier
Auto, 2.5, 3, 4~, 2, 2.4, 3.2, 3.33, 4+

~: 1066 MHz strapping, +: 800 Strapping MHz, #: 1333 MHz strapping

At the above settings in the exact place the MCH/FSB are strapped to the same timings.


FSB strap is a "start mark or set point" and ratio between the FSB and the Memory.

Actually a lower fsb strap will allow you to push the cpu further by increasing the FSB. While a Higher Strap will allow your RAM to run much faster.

Although the strap does specify latencies for the NB to run at the set strap levels, meaning if its the 1333Mhz FSB, it going to run with more lax timings then the 1066Mhz strap.

say you have a E6400 that has a default multiplier of 8.

well, you take the default multiplier, divide it by the multiplier you set, and then multiply it by the FSB you set, and then you get the Northbridge chipset clock.

so 8/8 x 400 = for 400 mhz or 1600 mhz on the chipset clock.

but then just lower the multiplier to 7, and stability should change cause your stressing the chipset even more.

8/7 x 400 = 457 mhz or 1829 mhz on the chipset clock.

even though all you did was change the multiplier.

so the default multiplier is the less stressful multiplier to use, but it's also the most limiting in most cases, cause it's easier to do 7x 500 then it is to do 8 x 500.


Your north bridge has an internal clock speed and latencies just like your CPU and memory. The FSB of your north bridge can be found by dividing your original CPU multiplier by your set CPU multiplier and then multiplying by your FSB.

So if you are running a E6600 (266 * 9) at 400Mhz x 8 your NB FSB is:

(9 / 8) x 400 = 450Mhz FSB (1800Mhz Total)

Just like your memory may be able to run at 4-4-4-12 at 1000Mhz but needs to run at 5-5-5-15 at 1200Mhz, your north bridge has a series of latencies which it must adjust in order to maintain stability at its FSB. These latencies seem to play a far more significant role in system performance than memory latencies.

Intel has predefined specific latencies at specific NB FSB speeds. They are referred to as straps. There is a strap for when the NB FSB is 1066Mhz and under, 1333Mhz FSB and under, 1600Mhz FSB and under, ect. When you go from the 1066Mhz FSB strap to the 1333Mhz FSB strap, the north bridge's internal latencies loosen to allow for greater stability.

ASUS has redefined the NB strap so that the 1333Mhz FSB strap does not come into effect until 401Mhz FSB (1604Mhz). Other perimeters of straps are someone unknown.

Tony, the guy who pretty much figured all this out and he works for OCZ. He is now a lobbyist trying to get ASUS and other major motherboard manufacturers to give the end user the control of when straps start.

There are 2 ways to beat the NB strap:

1. Boot to windows in the 1066Mhz strap and then use Clockgen to increase your CPU's FSB. You can then get to a much higher FSB while maintaining the 1066Mhz strap simply because the BIOS does not adjust the north bridge's latencies in real time.
2. Get a X6800 or QX6700 (or even a ES chip). To the north bridge, you are always at a default multiplier with a Extreme Edition processor. This allows you to set a much lower or higher multiplier without the NB FSB being effected.

EmilG
03-10-2008, 11:12 PM
Unfortunately the 4 multiplier is too high to be useful for me. I would like to have 3.33+, 3.33~ ,3.2+ and 3.2~ so I can get my CPU in the 3g-3.4g range with it's 9x max multiplier. The most my memory can go is around 1160. Do you know if the F8 bios has more options or if any are in the works?

Another question if you don't mind, what parameters does the "Performance Enhance" option affect?

Thanks for your time.

Lsdmeasap
03-11-2008, 02:48 AM
Use the 8 Multi

Performance Enhance effects memory bandwidth and overall systems speed, I suggest not using it at all until you are at a stable point. And then most likely since you are overclocking it will not be useful more then it is harmful.

But you can always try it and see after you are fully stable, but you may get the reboot cycle

EmilG
03-11-2008, 08:03 PM
Actually x8 does work well, I've run a couple passes of memtest through it at 380. The memory throughput is slightly less than the 334 combo(~100 MB/s) and I'd like the keep the NB as cool as possible. At 334x9/3.3 I'm getting 3g with memory at 1113m/5112MB/s. It's been running like this a couple days so I'm very happy with these settings :).

Seems my NB & Ram are able to run the tighter strapping at 334 and a strapping change is between 334 & 375. I did go to 333 looking for a boundary but it wasn't there, the mem speed decreased somewhat proportionately. All this is on the Extreme settings and with voltages forced to manual default so I'm lucky in those regards.

Although it probably isn't necessary I put a 40mm fan on the NB just to keep me happy.

Again a great board and an incredible value!

Thanks