4GB 2x2GB doesn't work with 2GB 2x1GB kit well ?

[russelharvey]

This is an Intel DG33BU micro ATX Mobo running Q6600 in Vista 64bit.

At beginning, the board has 2x1GB PC2-4300 and 2x512 PC2-4300, everything is fine. Thinking to increase the total memory to 6GB on board, first I bought the OCZ 4GB kit 2x2GB DDR2-6400 5-6-6-18, and replace the 2x512MB kit, the system became dramatically slow, CPU all 4 cores taking 100% often for simple activity such as open a file explorer. So I remove the 2x1GB PC2-4300 and leave the 4GB kit alone, then the system was running fine. At this point, I suspected the PC2-4300 will not work well with the OCZ 4GB DDR2-6400 kit, so I went to purchased a Consair 2x1GB kit DDR2-6400 5-5-5-12, again the system became slow with the same symptom.

When I have both OCZ 4GB kit and Consair 2GB kit on board, the OCZ showed as PC2-5300 in CPU-Z while Consair showed 6400, the OCZ memory requires adjustment memory voltage in bios in order to work in 800mhz (PC2-6400) according to OCZ support. Not sure if this is the problem causing the slowness, I have to replace the Mobo to either one of these following which support bios overclocking and voltage change:

1. GIGABYTE GA-G33M-S2H LGA 775 Intel G33

2. MSI G33M-FI LGA 775 Intel G33

Although I like MSI board's feature, almost everyone I asked told me Gigabyte is the one to choose, any advice in choosing among these two board?

Later on, someone from OCZ support claimed that the reason the system run into slowness is because I mixed 4GB kit with 2GB kit, so the memory setup such as 2x2GB won't work well with 2x1GB, it will have to be the same capacity, so either 4x2GB or 4x1GB. This is in contrary to what is commonly known as the momory setup that the board should support 6GB configuration with 4 slots, also my own experience (see above) with 2X1GB and 2X512MB.

However, I will purchase a 2GB OCZ kit today to try it with the 4GB OCZ kit I have, just to find out if the Consair and OCZ brand mixing would be the problem. Meantime, I am hoping the new motherboard allows me to adjust the voltage so once the OCZ memory runs in 800 mhz the problem maybe solved.

It's just hard for me to believe that mixing 2x1GB and 4x2GB can be the problem, or if this is A problem unique to OCZ memory? But then it seems OCZ is a highend mem vendor, should I get rid of OCZ memory alltogether and go with Consair memory instead?

Never can image upgrading memory can become such hard a job, thought all memory would just happily work togeter like we used to have with all the 1GB or 512MB PC2-4200 days when I can buy any vendor any size and it will simply work.

 

[rockyjohn]

I will leave the memory problems up to experts in that area, although I tend to agree with you. I ran other memory in 2 pairs of different sizes - even different speeds between the pairs - without a problem. I am GUESSING the problem is the timings or maybe voltages.

I see you contemplate purchasing G33 mobos. Do you need the onboard graphics? If not, you might save a little by getting the P35 chip without the onboard graphics. Better yet - if you can wait a week or two, Intel is about to introduce the X38 chip for enthusiasts - it has more PCIe channels and it will introduce PCIe 2.0 for the first time - a better long term upgrade option. Boards are already being advertised and sold - but there is still a dearth of information because of NDAs that expire soon - next week I think.

 

[zenmaster]

Concur with Rocky on both points.

 

[Falken699]

Basic answer: Always have identical RAM, in pairs, or all slots filled, to avoid voltage problems (ex. have 1x1x1x1 GB or 2x2 GB NOT 2x1x1). If you mix timings they all clock to the lowest one, and makes OCing tricky and unstable. But only the pros would notice any of this, even I wouldn't really see ANY difference in performance. The only time it would be tricky if I had cheap ram all mixed in and I wanted to push my CPU a few hundred more MHZ on the CPU, then my system may not post, or I would have to set everything even lower.

Rocky brought up many good points.

 

[russelharvey]

After tested with a Consair 4GB kit (2x2GB) and a OCZ 2GB kit (2x1GB), the slowness was reproduced in different combinatons, Consair 4GB + Consiar 2GB, Consair 4GB + OCZ 4GB, OCZ 2GB + OCZ 4GB. So the theory that 8GB will be OK or the problem only in 4GB+2GB scenario didn't not prove. in fact, 4GB + 4GB is not even stable, Vista randomly reboot a few times. The slowness is measured by stress testing range in 30% to 100 % depending on how many threads used. Speedfan displayed the cpu temperature averagely 10 degree higher than it is when a single kit (4GB or 2GB) is installed.

A subtle condition is, none of these memory has the same CL number, 4-4-4-12, 5-5-5-12, 5-6-6-18 etc. Wonder if the CL numbers have to match in order for different memory kit to work together? Now the only options left to be tested is what if and only if both kits are exactly identical, same brand, same model, same CL, same capasity, even it is, this is too absurd.

The reason I stayed in microATX board and G33 chipset (onboard video is not needed) is because the case and desk space. The sole purpose is to upgrade memory to 6GB, oc or memory tuning were not in the plan. However, it turned out a simple memory upgrading becomes a memory chip nightmare.

 

[miahallen]

I think it's a memory controller problem, do you have the latest BIOS? Are you replicating these problems on more than one board?

 

[russelharvey]

I've upgraded the intel DG33BU BIOS to its latest downloaded from intel web site. I plan to change the board to GIGABYTE GA-G33M-S2H LGA 775 Intel G33 as it allows some oc and memory voltage adjustment which is necessary to run OCZ memory in its max frequency.

 

[evongugg]

Read this article about Vista memory problems and a patch from Microsoft:

http://www.anandtech.com/showdoc.aspx?i=3060&p=1

 

[rockyjohn]

Like I said, I am NOT a memory expert - or even a a knowledgeable user - but I have had some limited experience. (Hopefully some expert will catch this thread and help out).
But in the meantime I am not sure if you want to purchase a new mobo until you understand the problem better. The memory might not work in the new mobo either.

I don't understand why the OCZ 800mhz memory requires adjusting the voltage to get it to work at 800mhz - but would understand if it is just the wrong memory for your mobo - that maybe the voltage does not match.
Is all the of memory you have and have tested rated as approved for you board by either the board or memory manufacturer? If the memory does not match the mobo requirements you could be putting round pegs in square holes.

I have always matched voltage and timing on memory and if you have different timings - the CL numbers - then it would not surprise me if it does not work together. You have all these electrons marching at what - thousands or tens of thousands per second - and you are trying to have them march together but at two different speeds. The poor drum major sees every thing getting bolexed up and throws up his batton and marches off. (This should show what a memory expert I am - my keen use of the correct jargon.)

Also I don't know if a board can provide different voltages or make different voltage adjustments per slot. I am sure that could be engineered - but why do it when it is easy to control that on the front end with the purchase of the memory. Did you ask OCZ about this?

Now maybe a new mobo can handle these memory variables - but you need to understand what you are asking it to do and make sure it can do it and you know how to make it do it before purchasing another mobo. It may be that you just need the matched memory - in either board. Have you checked to see if the current memory is compatible with the mobo you expect to purchase?

Oh great memory expert - come help us peasants!
(if you dont' get one soon - you might want to repost and make the title "Memory Expert Needed" - or maybe call OCZ - or maybe surf and read a little about memory)

 

[miahallen]

Read this article about Vista memory problems and a patch from Microsoft:

http://www.anandtech.com/showdoc.aspx?i=3060&p=1

He said he's running Vista x64, this article is dealing with limitations of x86.

This is an Intel DG33BU micro ATX Mobo running Q6600 in Vista 64bit.

 

[miahallen]

After tested with a Consair 4GB kit (2x2GB) and a OCZ 2GB kit (2x1GB), the slowness was reproduced in different combinatons, Consair 4GB + Consiar 2GB, Consair 4GB + OCZ 4GB, OCZ 2GB + OCZ 4GB. So the theory that 8GB will be OK or the problem only in 4GB+2GB scenario didn't not prove. in fact, 4GB + 4GB is not even stable, Vista randomly reboot a few times. The slowness is measured by stress testing range in 30% to 100 % depending on how many threads used. Speedfan displayed the cpu temperature averagely 10 degree higher than it is when a single kit (4GB or 2GB) is installed.

A subtle condition is, none of these memory has the same CL number, 4-4-4-12, 5-5-5-12, 5-6-6-18 etc. Wonder if the CL numbers have to match in order for different memory kit to work together? Now the only options left to be tested is what if and only if both kits are exactly identical, same brand, same model, same CL, same capasity, even it is, this is too absurd.

The reason I stayed in microATX board and G33 chipset (onboard video is not needed) is because the case and desk space. The sole purpose is to upgrade memory to 6GB, oc or memory tuning were not in the plan. However, it turned out a simple memory upgrading becomes a memory chip nightmare.

russelharvey,
All memory used at once will run on the same voltage, and with the same speed and timings. This means that you will need to set the BIOS according to the slowest RAM installed. All RAM can run slower than its rated speed, but most cannot run much faster (unless you increase the voltage).

 

[rockyjohn]

I think when I ran multiple sized of RAM I did not have to adjust the bios - it automatically adjusted the speed of all RAM to the slowest.

I did a little more reading and learned - or probably re-learned - that the different speeds generally have different timings - which means if one does mix speeds then one is mixing timings. Therefore I would be more suspicious of the voltages.

But where are the memory EXPERTS?

 

[russelharvey]

Concur to Rockyjohn and miahallen, the timing on CPU-Z confirmed this it automatically pick the slowest, or the frequency, I am not too clear, see my other post at OCZ forum: http://www.ocztechnologyforum.com/forum/showthread.php?p=232305

Also where I learned that the OCZ kit requires voltage adjustment to realize the max frequency (the beginning of that thread). In that example, I run the OCZ 4GB which has CL 5-6-6-18 and Consair 5-5-5-12, but in CPU-Z it shows as both at 5-5-5-15 (see the screenshot posted there).

Although I am not 100% agree with the OCZ expert's suggestion, which is, to match exactly what I started with so that I need to purchase another OCZ 4GB kit at 5-6-6-18, whereas 8GB is kind overkill to what I need, I prefer the OCZ 2GB but it's not 5-6-6-18, such as this. Besides, the CL timing seems has some relevance to the frequency, it may have different timing at 677 vs. 800mhz, I am guessing.

I'll go ahead apply the MS patch anyway as long as the OS doesn't stop me.

 

[miahallen]

Although I am not 100% agree with the OCZ expert's suggestion, which is, to match exactly what I started with so that I need to purchase another OCZ 4GB kit at 5-6-6-18, whereas 8GB is kind overkill to what I need, I prefer the OCZ 2GB but it's not 5-6-6-18, such as this.

If 6GB is not overkill for you now, 8GB will not be overkill for you soon, I'd follow their advise. Actually, I'm planning a system upgrade early next year, and I'm planning to go to 8GB myself, which is why I'm taking such interest in this thread. Thanks.

 

[evongugg]

He said he's running Vista x64, this article is dealing with limitations of x86.

This is an Intel DG33BU micro ATX Mobo running Q6600 in Vista 64bit.

Sorry to contradict, there is a fix for Vista x64 here:

http://support.microsoft.com/kb/940105

 

[russelharvey]

The GB G33M S2H Mobo just arrived, increased the memory voltage by 0.1v, chose 2.5 multipler (FSB 266), now OCZ 4GB kit runs at 800Mhz, added the Consair 2GB (2x1GB) kit, so far no slowness is found. Looks like this is a happy ending.

 

[miahallen]

I think it's a memory controller problem, do you have the latest BIOS? Are you replicating these problems on more than one board?

Awe, I think I was on to something there.
Thanks for updating us on the situation!