Resolved Memory timing problems and CPU runs hot.

The facts -

I have an older Intel D915GAV motherboard with P4 2.8Mhz socket LGA775.
It supports DDR2 at 333 and 400Mhz.

Recently I purchased 2 X CORSAIR 512MB memory sticks which are labeled as being 400Mhz 2225 (other markings CMX512-3200XL

When I installed them (with NO other ram installed) the BIOS detects them (automatically) as running at 333Mhz and the timing settings NOT 2225. I then set (in the BIOS settings) the following -

SDRAM CONTROL MANUAL AGGRESSIVE to that I could manually set the following (it was originally set to AUTO)
CPC OVERRIDE AUTO (I left this as it was as I have no idea what it does)
SDRAM Frequency 400Mhz
SDRAM tCL 2 (it was another value I can't remember)
SDRAM tRDC 2 ditto
SDRAM tRP 2 ditto
SDRAM tRASmin 5
I set these values as further down the screen where is displays what is installed in each slot these values were displayed.

The PC started to reboot occasionally and also display "a serious problem was detected ".

I used MEMTEST86 to test the memory which displayed no errors.

I then reformatted and reinstalled XP PRO SP3

The problems continued.

After googling the error message and reading up I decided that the problem could be memory related so REMOVED the CORSAIR memory and reinstalled the old memory which is 2 X 256Mb RamBo also labeled 400Mhz
I then noticed that the SDRAM CONTROL (BIOS) was reset to auto and the bios detects the ram automatically as 400Mhz and the latency as 3.0 3, 3 8.
The Corsair web site displays that the ram runs fast with extra low latency settings.

My questions -

Why does my motherboard automatically detect the CORSAIR ran as running at 333Mhz with different timings?

By changing the values manually could that cause problems within Windows?
Should I leave the BIOS to detect and set ram speed and latency automatically even though the speed is lower than what is labeled on the dimms? This would really defeat the purpose for buying the ram ie more capacity and at 400Mhz not 333

Lastly the CPU temperature runs between around 45C to 61C which seems to me to be rather high. I replaced the heatsink/fan (to a non INTEL one) with no change. Any ideas and do P4 LGA775 2.8Nhz usually run this hot?

 

Hi, a quick Google suggests 775 Socket may not support Dual Channel RAM. Does your CPU support this type of RAM? Neil.

 

From what I see there is no support for DDR2 only DDRSD Ram (or as some call it DDR1) and the important part is you have to make sure your BIOS is set for 2.6V and your DDR2 would not be 2.6Volt.
Here is a full explanation.

http://www.intel.com/support/motherboards/desktop/d915gav/sb/cs-027070.htm


The standard DDR2 voltage, as defined by the only legitimate standard there is, which is JEDEC, is in fact 1.8 volts. Memory that requires more, typically performance enthusiast types, does not conform to the industry standard, thus the need for tweaks in the BIOS to accommodate them.

 

Thanks for the quick replies.
According to the dox (downloaded from Intel)
Desktop Boards D915GAV and D915GAG:
* 2.6 V (only) DDR SDRAM DIMMs with gold-plated contacts
* Unbuffered, single-sided or double-sided DIMMs with the following restriction: Double-sided DIMMs with x16 organization are not supported.
* 4 GB maximum total system memory
* Minimum total system memory: 128 MB
* Non-ECC DIMMs
* Serial Presence Detect
* DDR 400 MHz and DDR 333 MHz SDRAM DIMMs

Intel® 915G Express Chipset

The CPU is P4 2.8Mhz Hyper Threading socket 775 operating at 800Mhz FSB

NOTE according to the CORSAIR web site the test voltage was 2.75v so the voltage seems to be ok

Please also note that I have Motherboard Monitor running and it displays the following voltages
label
+2.5V 1.48V <<<< this looks odd
VCore 1.29V
+3.3V 3.37V
+5V 5.10V
+12V 12.19V



And what about the high CPU running temperature?

 

Yes, your CPU temps are too high, even for a stock cooler, what compound did you use when re-seating?? Personally I stick with Arctic Silver, works good for me.
Make sure that you have a very thin and even layer.

What are your voltages set at in the BIOS

 

The compound used on the new heat sink was already applied to the heat sink when I opened it and the salesman also told me that it was).
I removed the heat sink tonight and the compound is now squashed leaving a thin grey layer.
I am wondering if the new heat sink works well enough as it isn't a genuine Intel and I think that the genuine one's have a copper core. I have another PC and it's CPU runs at around 34C (at idle) which is much more normal I think.

I will have to check the voltages in the BIOS later as the PC is currently doing a lot of installing and I don't want to stop it. (good thinking - MBM may not be reading correctly).

 

I am not familiar with Intel as I use AMD but I have used the compound supplied with AMD Coolers and I have found them OK running in the high twenties to mid thirties.
But as a general rule low to mid thirties is fine.
Does your new cooler have copper heat-pipes, I do prefer a copper base myself.
I would leave the timings alone until your CPU is running smooth at lower temps.

Some info on your Ram, that you have to run at 2.75V

http://www.corsair.com/_datasheets/cmx512-3200xl.pdf

 

For a PIV this temp. is normal. It ran very HOT so Intel had to drop plans for a 4 GHz chip.

 

The heat sink is a very standard one made entirely from aluminium from what I see. It was made in China and so just a generic one. I have read somewhere that the Intel ones (I had until I accidentally broke one of the pins which secure it to the motherboard) have either and/or a copper core. I also read I think that the heat sinks for the socket 775 P4 CPUs are larger than some others which makes me wonder if these chips had a reputation of running hotter than others.

What is the MAXIMUM temperature a CPU should run at SAFELY. Is up to 65C ok or not? I know that they have an inbuilt safety 'valve' which causes them to self shut down when too hot.

Also what is faster - 1Gb ram at 333Mhz or 512Mb at 400Mhz? Should I run the CORSAIR at the timings automatically selected by the BIOS (which is different to what is stamped on the dimms)? I have read that the CORSAIR ram can be set to low latency values for "gamers" and "overclockers ".
I assume from this data that low latency values result in faster speeds.
I have no knowledge of latency values and if PC speeds can be actually noticed for different latency values or if the ram speed (333Mhz or 400 Mhz - in this case) is more noticeable. Maybe I should look for more RamBo dimms and replace the Corsair ones.

Thanks again for everyone's input.

 

Here is a temp. guide

http://www.technibble.com/what-is-my-computers-maximum-cpu-temperature/

 

Thanks for that advice.

It would seem that my CPU is running no where near its maximum (runs 45C - 62C) but it certainly does run hotter than the CPU in my other PC (which runs around 25C - 35C).


I have also found an INTEL webpage listing ram modules found to work ok with the motherboard and most of them have a latency of 3-3-3 and 2.5-3-3 which is a bit higher than what they suggest for the Corsair modules so I will consider selling it and looking for some which is in the list of compatible ram or has a nown latency of 3-3-3 or 2.5-3-3 at 400Mhz.

I will now close this post.


Thanks again everyone.