Ram Question
By
Father Xmas,
Posted on: 2011-02-03 07:33 in ALL ACCESS Gameplay Technical Issues Bugs
Quote:
Well if you don't like going into your BIOS, then you might not be running at 5-5-5-12 in the first place. Use a utility like CPU-Z to see what the actual memory timings you are running at.|
Originally Posted by HotFlash
So I am thinking of adding more RAM to my system and I have a compatibility question. I currently have 4GB of 240 Pin DDR2-800/PC2-6400 SDRAM installed on my system running Win 7 64bit. It runs at 5-5-5-12 and 1.9V to 2.1V. It was made by A-Data and has been solid since I got it with no problems with it what so ever.
My problem is that this RAM is no longer available. Looking at NewEgg they have many 2 x 2GB RAM module packs to choose from. However none of them show them to run at 5-5-5-12. The closet I can see is 5-5-5-15. Does that matter ??? Does it have to be the same ??? Do I just need to bust out for 8GB of RAM to make sure there are no problems ??? I know you can go into the BIOS and change that or something but I don't like going there. Any info and or advice on this would be awesome. Thanks. |
"Standard" DDR2-800 is Cas 5, 1.8V. Not that the other timings after the first are insignificant, it's just that they don't impact performance anywhere near as much as the first number.
Pretty sure that the system will use the "worse" timings between two mismatched pairs but I'm not 100% sure.
Father Xmas - Level 50 Ice/Ice Tanker - Victory
$725 and $1350 parts lists --- My guide to computer components
Tempus unum hominem manet
Quote:
Depends on the motherboard.|
Originally Posted by Father Xmas
Well if you don't like going into your BIOS, then you might not be running at 5-5-5-12 in the first place. Use a utility like CPU-Z to see what the actual memory timings you are running at.
"Standard" DDR2-800 is Cas 5, 1.8V. Not that the other timings after the first are insignificant, it's just that they don't impact performance anywhere near as much as the first number. Pretty sure that the system will use the "worse" timings between two mismatched pairs but I'm not 100% sure. |
Some read the first dimm slot and run everything else at that speed. Easy enough to adjust in bios. I doubt there would be a problem mixing them. It is really a very minor diferance in speed. Worse case you might need to move the dimms around to get them to work (though I doubt it).
Going from 2 to 4 dimms its also possibly you might need to up your voltage a small amount to stay stable too.
So, should I just get any old 4GB of DDR2800 RAM and hope for the best ??? Not sure on this one. Gonna do more research as well.
Keeping it Brutal !!!!!!!!
IIRC for *best* compatiblity you should get properly paired sticks of RAM, ie produced from the same manufacturer and ideally from the same batch as well... ie so that all the timings match up
Now saying that, you can basically just slot in "any" 2GB DDR RAM in, and the BIOS *should* auto adjust the timings to the slowest.
You can also "overclock" the timings via the BIOS, but with mixed speeds you might not see as much of an advantage.
Oh, and any perfomance hit that you would lose out on due to mismatched speeds'' you are more likely to make back via the increase in RAM.
Quote:
I've mixed and matched ram for years. I know the by the book best method is for everything to match, however buying piece by piece makes it difficult. That said I do try and make an effort to make sure all my dimms are rated for the same speed. eg PC 6400 etc. |
Originally Posted by Gangrel_EU
IIRC for *best* compatiblity you should get properly paired sticks of RAM, ie produced from the same manufacturer and ideally from the same batch as well... ie so that all the timings match up
Now saying that, you can basically just slot in "any" 2GB DDR RAM in, and the BIOS *should* auto adjust the timings to the slowest. You can also "overclock" the timings via the BIOS, but with mixed speeds you might not see as much of an advantage. Oh, and any perfomance hit that you would lose out on due to mismatched speeds'' you are more likely to make back via the increase in RAM. |
Your very right about the extra ram making up for a slight change in the timings.
really DDR2 is at the end of its lifetime. All of it being sold now has had its bugs and problems worked out years ago. At this point in the product life span everything being sold is manufactured to the same specs and some is made into higher speed and some lower depending on the orders.
The only problem I have ever had maxing out my ram (at 8 gigs) is needing to up voltage, I am running at 2.05 volts instead of the default 1.8 to fix some stability issues. Then again my motherboard has a rep for being 'picky' about memory.
The brands I have had the best results with are crucial and mushkin.
Opps, knew i forgot to mention that the RAM speed should be the same, cos otherwise it will by default drop down to the slowest speed slotted.
Also making sure that its all "paired/tripled" up correctly (for DDR3 RAM) as in with 4 slots you would want 2 pairs, or 2 triplets of same speed for proper DDR access
ie for DDR2 RAM and 4 slots,
2x1GB and 2x2GB for 6GB total is just fine,
but 3x2GB is bad as you wont be getting DDR benefits.
No, you won't get dual channel benefits.
DDR means double data rate, that is two bytes of memory read/or written for every cycle of the clock.
Dual channel means that two sticks of memory can be accessed at the same time for improved bandwidth. Triple channel, found in the i7-9xx, means three sticks of memory can be accessed at the same time.
Father Xmas - Level 50 Ice/Ice Tanker - Victory
$725 and $1350 parts lists --- My guide to computer components
Tempus unum hominem manet
Quote:
Are they fighting to the death?
|
Originally Posted by Father Xmas
Duel channel
|
This thing has been logging me out everyother minute today. I surprised I was able to post at all.
Father Xmas - Level 50 Ice/Ice Tanker - Victory
$725 and $1350 parts lists --- My guide to computer components
Tempus unum hominem manet
Quote:
Ya, there is a thread on that.|
Originally Posted by Father Xmas
This thing has been logging me out everyother minute today. I surprised I was able to post at all.
|
Dont forget each DIMM is two banks of ram. Having all the dimms the same size across banks can increase speed too by allowing all the banks to be interleaved rather then each dimm/bank.
Check out your bios options for memory management. After you find the jumper to clear cmos, just in case, you can try out the more aggressive interleave options. Hmm, I need to go double check what mine is set to.
So I am thinking of adding more RAM to my system and I have a compatibility question. I currently have 4GB of 240 Pin DDR2800 - PC26400 SDRAM installed on my system running Win 7 64bit. It runs at 5-5-5-12 and 1.9V to 2.1V. It was made by A-Data and has been solid since I got it with no problems with it what so ever. My problem is that this RAM is no longer available. Looking at NewEgg they have many 2 x 2GB RAM module packs to choose from. However none of them show them to run at 5-5-5-12. The closet I can see is 5-5-5-15. Does that matter ??? Does it have to be the same ??? Do I just need to bust out for 8GB of RAM to make sure there are no problems ??? I know you can go into the BIOS and change that or something but I don't like going there. Any info and or advice on this would be awesome. Thanks.
Keeping it Brutal !!!!!!!!