# 1Gb DDR2 = ok. 2Gb = crash [SOLVED]

## stuorguk

I have 2 x 1Gb DDR2 Ram.  Together they ran without fail with Memtest86 for 8 hours.  However, under heavy load, such as compiling, my computer locks up, or resets itself.

If I run the computer with just one DDR2 installed (and I have tried both), it's stable.

CPU: 2 Core Duo

Kernel: 2.6.19-rc6-mm2

Any ideas?

StuartLast edited by stuorguk on Wed Jan 17, 2007 6:13 pm; edited 1 time in total

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## Keruskerfuerst

1. Power supply is not working correctly. A good (and not cheap) power supply e.g. from Seasonic or BeQuiet is a very good choice.

2. The switching power circuit for the CPU (contained on the mainboard) does work correclty.

3. The CPU cooler is not sufficient. A cooler from e.g. Scythe (Scythe Mine cooler) is a very choice.

4. The temperature in the computer case is too high.

5. The memory is not recognized correctly or the Ram modules are installed in the wrong memory slot.Last edited by Keruskerfuerst on Wed Jan 17, 2007 12:34 pm; edited 1 time in total

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## stuorguk

 *Keruskerfuerst wrote:*   

> 1. Power supply is not working correctly. A good (and not cheap) power supply e.g. from Seasonic or BeQuiet is a very good choice.

 

I have a new Seasonic 600W PSU. (Great minds think alike  :Wink:  )

 *Quote:*   

> 2. The switching power circuit (contained on the mainboard) does work correclty.

 

Dunno

 *Quote:*   

> 3. The CPU cooler is not sufficient. A cooler from e.g. Scythe (Scythe Mine cooler) is a very choice.

 

Watercooled. (I like my computers to be quiet).  Besides, I would have thought it unlikely the CPU runs hotter with 2Gb

 *Quote:*   

> 4. The temperature in the computer case is too high.

 

Nope.  Case is open right now.

 *Quote:*   

> 5. The memory is not recognized correctly or the Ram modules are installed in the wrong memory slot.

 

Would have thought Memtest86 would have picked that up.

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## Keruskerfuerst

 *Quote:*   

> Kernel: 2.6.19-rc6-mm2 

 

Why are you using this kernel and not 2.6.19.2?

What type of mainboard do you have?

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## stuorguk

 *Keruskerfuerst wrote:*   

> Why are you using this kernel and not 2.6.19.2?

 

I need reiser4 support.  It's a good point though.  I did try the more recent 2.6.20-mm series, but found them to be very unreliable.

Are there any Kernel options I should be looking at?  There is a setting for Flat or Sparce memory - I have it on Flat.

Stuart.

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## Keruskerfuerst

1. Kernel preemption: try to set it to off. 

2. Flat memory is the usual setting. Sparse memory is for NUMA systems.

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## Paapaa

And I guess you have support for 4GB memory turned on?

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## stuorguk

 *Paapaa wrote:*   

> And I guess you have support for 4GB memory turned on?

 

Can't find that option, but I have 2GB in total (2x 1GB).  I should also point out, that I am using a 64bit kernel.

Stuart.

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## November Rain

I think your ram modules use  dualchanel. check the timings in the bios. I had the same problems, because my ram modules are optimized for nforce boards and i have a via chipset.

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## stuorguk

 *November Rain wrote:*   

> I think your ram modules use  dualchanel. check the timings in the bios. I had the same problems, because my ram modules are optimized for nforce boards and i have a via chipset.

 

Thanks, I'll look into that.

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## Naib

check the BIOS config for yr ddr2, mobo manufacturers tend to be very conservative

sure the timing wont cause any problems, but the voltage would.

I kept crashing out until I read that they are conservative, got CPU-Z (and a couple of other apps for BIOS-checking) and saw that the timing was slower (5-5-5-15 and not the 4-4-4-12 my RAM can do) as well as running at 1.8V !!!  most DDR2 like 2.1V 

since my RAM likes 2.1V (says it on the stick as well) upped it and everything fine since

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## luqas

 *Naib wrote:*   

> check the BIOS config for yr ddr2, mobo manufacturers tend to be very conservative
> 
> sure the timing wont cause any problems, but the voltage would.
> 
> I kept crashing out until I read that they are conservative, got CPU-Z (and a couple of other apps for BIOS-checking) and saw that the timing was slower (5-5-5-15 and not the 4-4-4-12 my RAM can do) as well as running at 1.8V !!!  most DDR2 like 2.1V 
> ...

 

Exactly.  I had problems with my new C2D system when I built it and could not figure out why.   I looked at my mem voltage (which required 2.1v) and it was set to 1.8v in the BIOS by default.

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## stuorguk

FIXED!   :Cool:   It was indeed DDR2 memory voltage.  I pushed it up a little.

Thanks all. 

Stuart.

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## Paapaa

Just for the record: what is the brand and model of the memory you are using?

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