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Unequal RAM does not work
Posted: Tue May 15, 2007 9:27 am
by Fizz
Hi !
I have a T60 D6U2623 machine which came with 512MB RAM. I recently bought 1 GB of Kingston RAM with the same specs (667MHz DDR2 Non-ECC CL5 SODIMM PC-5300).
Since I added the 1 GB stick the T60 hangs up very often, esp when playing CnC3. Nothing will work and even the Dr.Watson log will show up empty after a hard restart. This also happens when not playing.
Resolution: I have tried running each RAM separately and they work fine. Changing the slots doesn't seem to work either. There are no errors on running Memtest for 25 cycles and all the RAM is recognized by both the BIOS and XP.
Any ideas

Posted: Tue May 15, 2007 9:46 am
by ryengineer
Thinkpads are very picky machines and won't accept memory of various makes. Your both memory modules are not compatible with each other.
Posted: Tue May 15, 2007 10:13 am
by whizkid
I'd say your beef is with Kensington, even though the machine works fine with that part alone.
The onus is on Kensington to ensure their memory not only works in the machine, but that it works with the memory that ships in the machine.
Get them to fix it.
Posted: Tue May 15, 2007 10:53 am
by pianowizard
I have one 1GB Samsung and one 1GB Kingston in my T60 since three months ago. Haven't had any issues. I also had one 1GB and one 512MB of two different brands for a while (I forget what brands they were), and again, no problems.
Posted: Tue May 15, 2007 11:31 am
by Fizz
pianowizard's case shows that it can be done. ryengineer thinks otherwise. 1-1...
However, is there any software that can show up memory mismatches or other subtle RAM mismatch ?
Posted: Tue May 15, 2007 11:44 am
by ryengineer
To support my claim, I have personally experienced this problem and see what these people (below) have to say on this forum, even Bill the host of this forum had similar issue which he solved by replacing them with another brand.
Here
Here
Here
Just search around the forum you will come up with a lot of threads.
PW is right in his way, this problem only happens with few mobo/memory configurations. Imagine like some human bodies are not capable of accepting all blood types but only few.
Posted: Tue May 15, 2007 12:03 pm
by Fizz
Thanks for the heads up ryengineer

I did check all the links you sent. So the only option seems to be keeping 2 RAMs of the same type and brand in the Thinkpad. BIOS and video card options don't really seem to solve this issue.
It would be nice if these things were made clear at the IBM website itself. I had checked there before buying this RAM and there were no hints to the contrary. The only requirement was for same type of memory which I did get.
Is there anyway to find out the detailed specs of both RAMs ? Maybe hidden somewhere deep inside, these are not really the same ?
Posted: Tue May 15, 2007 12:18 pm
by laundromatt
i personally have a 1GB patriot and a 1GB kingston coexisting peacefully in my T60.
you might want to check the long 2 x 1GB lock up thread. it might answer some questions.
Posted: Tue May 15, 2007 10:24 pm
by Fizz
On using RightMark Memory Analyzer and CPU-Z, I find that the timings on my new Kingston 1 GB RAM are 5-5-5-15 while the Micron (original) is 5-5-5-12. Maybe thats making all the difference
pianowizard and laundromatt, have you ever checked if the timings on your RAM modules are the same ? That would explain this incompatibility

However, unlike the 2 x 1 GB lock up thread, I dont see any way IBM is going to replace the original

Posted: Wed May 16, 2007 2:52 am
by laundromatt
which version of cpu-z are you using? my version won't tell me the timings of each stick.
Posted: Wed May 16, 2007 7:01 am
by Fizz
I used CPU-Z version 1.40 and RightMark Memory Analyzer version 3.72.
Posted: Wed May 16, 2007 10:24 am
by jagged
Hmm...I used to have a 2623D6U and had a 512MB and 1GB RAM on it but it didn't give me any problems.
Hope you can solve your problem soon.
Posted: Wed May 16, 2007 1:50 pm
by laundromatt
Fizz wrote:I used CPU-Z version 1.40 and RightMark Memory Analyzer version 3.72.
it doesn't look like 1.40 tells you the timings for each stick either.
it just has one MEMORY tab for what i'm assuming is the current state of the system. for that page, i'm reading 5-5-5-15-21. i don't know if that was what it was with just the patriot stick...
Posted: Wed May 16, 2007 4:17 pm
by Fizz
CPU-Z: The 5th tab called SPD is where you can select the memory slot. You can then change the memory slot selection and then view the results in the Memory tab (4th tab).
Re: Unequal RAM does not work
Posted: Wed May 16, 2007 4:21 pm
by starlights
Fizz wrote:Hi !
I have a T60 D6U2623 machine which came with 512MB RAM. I recently bought 1 GB of Kingston RAM with the same specs (667MHz DDR2 Non-ECC CL5 SODIMM PC-5300).
Any ideas

If the Kingston Ram you bought is what they call the "value ram" you will get pretty inconsistent results.
I had recently installed 2 1GB sticks of Kingston Value Ram in my T60 (same specs as listed by you) and sometimes the machine would power up, but mostly not. Even when it did power up, it would sometimes freeze later on.
Swapped the kingston sticks out for Patriot and everything works normal now - just my 2cents.
Posted: Wed May 16, 2007 4:37 pm
by carbon_unit
Unless you do some very extensive testing, mixing ram is a "Luck of the draw" situation. It might work fine, it might not work at all, it might seem OK for a while and then you may notice "odd things".
The only way for most people to get guaranteed results is to buy ram that is "guaranteed compatible" and even then things
could go wrong.
I have seen computers that seem to run OK but the owner wanted more memory so we replaced all the memory with bigger sticks (matched) and some "flakey things" went away.

Posted: Wed May 16, 2007 9:34 pm
by pianowizard
carbon_unit wrote:The only way for most people to get guaranteed results is to buy ram that is "guaranteed compatible" and even then things could go wrong.
Very good point. That's why the best places to get affordable modules are crucial.com and 18004memory.com.
Update
Posted: Sat May 19, 2007 10:13 am
by Fizz
I checked the RAM timings with CPU-Z and both 1 GB and 512 MB sticks come in at 5-5-5-15 clocks ! Thus one can't really explain it on timings any longer. Maybe it's just luck as some have pointed out.
However, I did get a BSOD last time with the message
STOP: 0x00000050 (0xD667BE2C, 0x00000000, 0xBFB56F56, 0x00000000)
ati3duag.dll - Address BFB56F56 base at BFAA5000, DateStamp 4507fb99
Now I wonder if its just a matter of the graphics card and not the memory as some have alluded to ? Will check up and keep updating the thread.
Re: Update
Posted: Sat May 19, 2007 10:35 am
by crazyfrog
Fizz wrote:I checked the RAM timings with CPU-Z and both 1 GB and 512 MB sticks come in at 5-5-5-15 clocks !
You'd better check the RAM timing with each ram installed stand alone.
I just noticed that the same Samsung ram comes in at 5-5-5-15 with a ProMOS ram, while it is 5-5-5-13 with another Samsung ram. Maybe the RAM timing depends on which one is a little "slower".
Re: Update
Posted: Sat May 19, 2007 11:52 am
by Fizz
crazyfrog wrote:Fizz wrote:I checked the RAM timings with CPU-Z and both 1 GB and 512 MB sticks come in at 5-5-5-15 clocks !
You'd better check the RAM timing with each ram installed stand alone.
I just noticed that the same Samsung ram comes in at 5-5-5-15 with a ProMOS ram, while it is 5-5-5-13 with another Samsung ram. Maybe the RAM timing depends on which one is a little "slower".
Well, there is a difference but its in the Bank Cycle Time (TRC) which is 21 clocks in the 1 GB stick and 5 clocks in the 512 MB stick...maybe that the difference that is causing incompatibility...
