Ram speed & timings

[Tullphan]

Ok...i'm shopping for some DDR2 800 ram.
When looking at the various manufacturers for that particular speed, Cas latency comes into play. Some advertise a Cas 4 (4-4-4-12 @ 2.0V) & some advertise a Cas 5 (5-5-5-15 & sometimes 18) @ 1.8V.
I've been told one needs memory that will boot @ 1.8V, so what's up w/the speeds? What Cas latency does a TRUE DDR2 800 run at? I don't want to purchase an overclocked DDR2 667.
I hope i'm making sense...hehehe.

 

[milnen]

Almost any high performance memory operates at voltage higher than 1.8V, typically 2.1 - 2.3 V. Don't worry, it is projected to operate at higher voltage.

 

[Tullphan]

So when shopping for DDR2 800, do I look for 4-4-4-12 @ 1.8V...or is that possible?

 

[NXIL]

http://www.newegg.com/Product/...x?Item=N82E16820208329

 

[HardWarrior]

I hope someone who really knows memory responds to this thread.

I just picked up 4 of these. They're CAS4.

GSkill-newegg

 

[JustaGeek]

HZ series by G.Skill w/ Micron D9 IC's.

Great memory. Running 2 x 1GB + 2 x 512MB for a total of 3GB of RAM on 32-bit XP.

Should boot at 1.8V without a problem. Currently running at 2.0V, 800MHz at 4-4-4-12-2T.

Don't know much about the AMD platform, but will try to answer any questions you may have.

 

[BonzaiDuck]

Generally, this business of memory latencies is a crap-shoot which benefits from some research on what others have done -- or proven -- with regard to various modules.

To help you understand something about memory timings, I'm throwing out this old THG article from 2003 on RAM timings. At that time, the prevailing spec was DDR memory, and even RAMBUS had yet to die, but these are the essentials -- the principles. There are later articles -- I leave it to you to locate them:

Tweaking RAM latencies

What the manufacturer says are the "spec latencies" are usually -- or often -- looser than what the modules are capable. Further, there is a trade-off between speed in Mhz and latency timings -- for a higher speed, looser latencies are required. But you can improve the bandwidth speed of your memory be tightening the latencies.

About the best way to assure yourself of the greatest "timing-tweak" potential is to scour reviews on promising memory modules, and often, the reviewers will provide an index of latency settings for the reviewed modules that work at different speeds --above, below and at the manufacturer Mhz spec.

 

[BonzaiDuck]

Incidentally, these are a great bargain right now:

Crucial "NewEgg LanFest 2GB kit"

They're a bargain for a couple reasons -- first, these are high-end modules at a modest price, and you get the double-whammy of a $25 MIR.

But also, these aren't some "off-brand" punchouts that Crucial just slammed together to support Newegg. If you check the product code following the prefix ending in "KIT," then search the Crucial website, you find that these are:

DDR2-800 TRACERS

Newegg must be chuckling, since a Newegg-search for DDR2-800 modules by Crucial will turn up the re-badged Tracers and the "retail" Tracers on the same page, for the unabashedly, shamelessly different pricing.