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JoeW
March 15th, 2010, 06:44
I have a dumb question. Which is faster, a cas of 4, 5, or 6?
I'm about to purchase 4 gigs and am a little bewildered at the choices.
Thanks

spotlope
March 15th, 2010, 07:24
I'm pretty shaky on this stuff too, but I believe lower numbers are faster. It's a latency measurement, and less latency is always better. What I don't quite get is why the number changes depending on FSB speed. For instance, I bought what was labeled as 5-5-5-15 RAM recently, but when I run it at a bus speed of 400, it becomes 6-6-6-18. Maybe some tech guru can chime in w/more info.

warchild
March 15th, 2010, 09:04
The number discrepency is easy. You bought ram that was able to work faster than your motherboard, so in a sense, your ram speed was "throttled" back to the maximum speed that the motherboard could function at..
CAS i'm afraid i have no clue on.. i never use it as a defining term, but then i'm no longer as detailed as i used to be..

Roadburner440
March 15th, 2010, 10:23
I am no expert either on this by any means, but the lower the number the faster the RAM is. There are plenty of good websites that tell you how to tweak your RAM speeds through DOS with a quick google search. I didn't know you could get RAM that was to fast for your motherboard though. Thought you could just get the mhz end of it that was to fast? It maybe also that you mixed RAM, and the computer is clocking your new RAM stick to match the speed of your old one, because your RAM can only be as fast as the slowest stick installed in the computer. That is why it is always good to remove/install in sets. You can also overclock the memory and that allows you to lower the settings for CAS, and such in the DOS menu. Then you run into problems with burning it up though. It is just best to figure out what your bus speed is, get RAM that matches that mhz the best you can, and then get a decently low latency without breaking the bank. www.newegg.com (http://www.newegg.com) usually has some good deals. I have gotten processors and other parts through them with no hassles.

JoeW
March 15th, 2010, 13:53
The specs on the MB that I'm using are that it will handle 2- 1.8v DDR2 sticks of up to 4 Gigs total. It has dual channel memory architecture. It supports DDR2 800/667 memory modules.
The front side bus is supposed to run at 1333/ 1066 /800 Mhz. It will take any LGA 775 socket CPU.
My next question is ...... How do you control the FSB? How do you get it to run at 1333 Mhz when your using 800 mhz memory?
I'm trying to catch up on this new terminology.

Major_Spittle
March 15th, 2010, 14:37
Get 1.8v DDR2 800, the lower the cas number the better it will perform buy you won't see that big of a diff. between CAS 4 vs CAS 5 ie 4-4-4-12 vs 5-5-5-15 are the flavors you probably see. Don't spend much extra for a low CAS.

This would be a very good choice for RAM for the computer you described: http://www.newegg.com/Product/Product.aspx?Item=N82E16820211188 It meets DDR2 specs and should work in virtually all Motherboards that adhere to DDR2 specs.

If your Mother Board supports those different FSB speeds it will automatically default to the correct one for the processor you have installed.

Good luck

harleyman
March 15th, 2010, 14:45
I have a dumb question. Which is faster, a cas of 4, 5, or 6?
I'm about to purchase 4 gigs and am a little bewildered at the choices.
Thanks


Jow... For FSX you want the lowesr CASS..

The timings are all adjustable and overclockable ...