RAM Buying help

T

TheLostOne

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Hello

I am planning to upgrade to Win 7 64bit. I have some doubts about the hardware as I intend to expand the RAM capacity.

I have the following motherboard: ASUS P5B-VM (http://www.asus.com/Motherboards/Intel_Socket_775/P5BVM/#specifications). I already have three RAM modules installed (1 GB each, DDR2-667/PC25300). There are 4slots and each can take up to 2GB each, total 8GB. In the last slot, I am planning to add a 2GB RAM, but I have doubts about the following which unfortunately I could not clear from the supplied instruction manual of motherboard. Please help me on the following:

1. How can I find the detailed specification about my installed RAM from within the OS (Win XP Pro)?

2. The manual mentions that I can install varying memory sizes in slot, but what I am not clear about whether I can install varying type like DDR2 800/PC2-6400 (like this one: http://www.flipkart.com/browse/computers/components/ram-20214?filter=device_fa%3APC%3E%3Edata_rate_fa%3ADDR&ref=45a9f79c-2f6a-48b4-8cfe-cdfa5a115fa9) with my existing modules. This module seems to have the Cas Latency as my existing ones 5-5-5-15.

3. The following is written in the manual as "Notes on Memory Limitations" which I could not understand. I am quoting the text as follows:

"Due to memory limitation, this motherboard can only support up to 8GB on the operating system listed below. You may install a maximum of 2 GB DIMMs on each slot, but only DDR2-533 and DDR2-667 2GB density modules are available for this configuration."


32- bit
64-bit
Windows© 2000 Advanced Server
Windows© XP Professional x64 Edition

Sorry, but I could not make anything out of it. Does it mean that I can not install a DDR2-800 RAM module with my existing DDR2-667 RAM modules?

Please help me on this.

Thank you
 
Ill just follow you over here I guess.

Your going to need to change your memory configuration to get the most out of the upgrade.
At the very least drop one of the 1GB and pick up 2x2GB. So you will have 2x1 ad 2x2 giving you 6gb.

As far as RAM speed goes your going to be limited to 667Mhz as that is the slowest part.

Also with 3x1GB your not running in dual channel mode, its called something else but the name escapes me. I don't think it gives you the performance of true dual channel.
But I could be totally wrong on that.

Best solution replace with 2 (2x2GB) DDR2-800 for 8GB RAM. But this may or may not be "officially" supported.

What they mean by
"Due to memory limitation, this motherboard can only support up to 8GB on the operating system listed below. You may install a maximum of 2 GB DIMMs on each slot, but only DDR2-533 and DDR2-667 2GB density modules are available for this configuration."

Is that the Qualified Vendors List of RAM does not have any 2gb DDR2-800 modules on it.
So it was not officially supported at launch but that may mean anything.
I would check with someone from ASUS.
 
1. CPU-Z should give you details about the RAM.
2. You can run 667 and 800 ram in the same system, but it will revert to the slowest speed ie 667. I would just as soon go all 667 or 800.
3.That refers to the Qualified Vendors List . I will assume that those are the verified RAM modules you can use. I highly doubt that you would have an issue with RAM that is not listed there, but it is not officially supported.

You could call ASUS and ask, or go to a B&M store that does not have a restocking fee and pick up some 800 ram and test it. Return it if it doesn't work and only buy 667.
 
thedocta45 said:
1. CPU-Z should give you details about the RAM.
2. You can run 667 and 800 ram in the same system, but it will revert to the slowest speed ie 667. I would just as soon go all 667 or 800.
3.That refers to the Qualified Vendors List . I will assume that those are the verified RAM modules you can use. I highly doubt that you would have an issue with RAM that is not listed there, but it is not officially supported.

You could call ASUS and ask, or go to a B&M store that does not have a restocking fee and pick up some 800 ram and test it. Return it if it doesn't work and only buy 667.
Click to expand...

Thanks for the reply.

Sadly, I do not have the privilege of accessing B&M store in my country. :(
And, ASUS service simply is too bad in our country, there is almost no chance that they will be able to tell me anything technical about this product, which in terms of PC HW standard, pretty "old".

So if I buy a 2GB DDR2-800MHz RAM module there would be no problem, except that the 800MHz one will run at 667MHz (as I do not have problem with all my RAMs running at 667 MHz). At present I can not replace all my RAM modules to this 2GB RAM module as the DDR2 RAMs are priced pretty steep.

What about Latency values? I know that according to the manual, I need to buy at least 5-5-5-15 CS value RAM to make that run proper. All my three existing modules have 5-5-5-15 CS value. If I install the new RAM module with >5 CS value, will there be any problem?

Thanks again.
 
My recommendation considering your limitations:

1. Forget 800 Mhz
2. Just get (2x2 GB) 667 Mhz with the 5-5-5-15 timings, and play it safe.

Reasons:

1.As you mentioned in your previous post the issue is not really a speed issue but a physical limitation on RAM.
2. Unless your replacing all the RAM you wont even see a change. In overall RAM speeds.

Best solution go 2x1GB and 2x2GB of 667 5-5-5-15. 6GB will be a nice boost, remember to run 64bit CS as well.
 
Thanks for the reply and suggestion, I really appreciate it.
Sadly, today I searched my local market but there is no RAM module of DDR2-667MHz from any standard manufacturer. Whatever I found does not even mention the Latency Value. SO I think I have no option but to buy 1 or 2 2GB DDr2-800 MHz RAM modules.
Could you please comment on the following one:

G.Skill NT DDR2 2 GB (1 x 2 GB) PC RAM (F2-6400CL5S-2GBNT): http://www.flipkart.com/g-skill-nt-...JX6V&ref=54ba65b3-38fb-4e15-bc90-390b16b13186

Thanks again
 
Thanks again.
Would you please take a look at this RAM (DDR2-667 MHz, available in my country): http://www.flipkart.com/transcend-d...2MPX&ref=898871bf-6a7d-4a8e-88a0-3d6335cf3b14
This mentions that it's CAS Latency is 3,4,5. Now I have downloaded the official Specification of this module (searching by the part number) and found that it is written there:
Programmable CAS LATENCY: 3,4,5
What does it mean by Programmable CAS Latency? Does it mean that I can program the CAS Latency according to my requirement? Or is it the CL values respective to specific FSB value like for frequency 200 MHz CL=3, 266 MHz CL=4 and 333MHz CL=5?

In case you require please find the Specification sheet for the above mentioned RAM Module here: http://www.google.co.in/url?sa=t&rc...rAWEAGwvAH0IG2jcQ&sig2=P_8vHXF93kghCtqv8EWLog
Please understand, it is very important for me to ascertain the compatibility of the above mentioned memory module. If the above module can work with my present one, that would take a lot of trouble off me as at present finding the DDR2 DIMMs in the market in our country is very hard (and pricey too).
Eagerly waiting for your reply
 
Please be kind enough to explain the following:


"This motherboard does not support memory modules made up of 128Mb chips or double sided x16 memory modules."
Click to expand...

But all the memory modules that I have checked (of 2GB capacity) are made with 128Mx8bit DDR2 SDRAM....

So will the kind of DIMM mentioned above (with URL) be supported? If this is not supported, then no DIMM module of 2GB size can be supported, because afaik all 2GB modules are made with 16x128M chips with 8 chips on each side.

Please help me out. :(
 
Sorry crazy weekend and my internet is down after just being installed.
Programmable should mean you can set the timings in the BIOS, I honestly don't know for sure.

If it says that it is not supported then you might not be able to upgrade.
I would definitely give a call over to ASUS, and see what they say.
It sounds like a weird specification to have as you point out most all 2GB DIMS are 128mb chips.

Okay here is the thing, the QVL does not have any RAM that is in the 2GB size. I misread the 256MB DIMS as 2GB.
At this point your best off getting that RAM you linked see if it works, and cross your fingers.
Hopefully they have a good return policy.
Again calling ASUS at this point might be your best bet.

It doesn't look good alot of people have issues running 8GB on the board.
Here is one that reportedly works.
Using 2*CT2KIT25664AA667 from Crucial
Its 256Meg x 64 so it is not 128MB nor x16

http://www.amazon.com/Crucial-CT2CP25664AA667-240-pin-PC2-5300-Memory/dp/B000SOVVUQ 46.85
 
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