09-06-2003, 02:19 PM | #1 (permalink) |
Insane
Location: A fuzzy cloud.
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Trying to understand DDR ram...
Memory: Supports DDR 200/266/333 via 2 184-DIMM slots for up to 2 GB.
This is for the ICE Cube bare bones mini PC on thinkgeek.com Is the 200/266/333 the bus speed? or what? I always see PC 3200, 2700, etc when I look for DDR ram.. |
09-06-2003, 07:02 PM | #2 (permalink) |
Just here for the beer.
Location: Ft. Lauderdale, Floriduh
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Here's a pretty good explanation:
http://www.white-chocolate.com.au/Ma...rexplained.htm Hope that helps.
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09-06-2003, 08:31 PM | #3 (permalink) |
Knight of the Old Republic
Location: Winston-Salem, NC
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Yes, the 200/266/333 is the front side bus speed of the RAM. The faster the better, of course. PC2100 is 266 MHz FSB, PC2700 is 333 MHz FSB, and PC3200 is 400 MHz FSB. The ram names (2100, 2700, etc.) are simply there to recognize which type of RAM it is, much like AMD Athlon XP processors. An Athlon XP 1900+ doesn't run at 1900 MHz, it runs at 1600 MHz or 1.6 GHz. Just like the Athlon XP 2500+, which runs at 1.8 GHz, not 2500 MHz.
-Lasereth
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"A Darwinian attacks his theory, seeking to find flaws. An ID believer defends his theory, seeking to conceal flaws." -Roger Ebert |
09-07-2003, 12:34 AM | #4 (permalink) |
42, baby!
Location: The Netherlands
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It's even worse: 200/266/333/400 is *not* the FSB (front-side-bus), but is 2 * FSB, because it's "double-data-rate" memory. DDR200 runs at 100 Mhz, DDR266 at 133, 333 at 166 and 400 at 200.
That's similar to the supposed 800 Mhz FSB of the new Intel P4's with Hyperthreading: that's actually 4 * 200 Mhz FSB... The PC2100/PC2700/PC3200 shows you the maximum "speed" of the memory in MB/s. DDR400 (2*200 Mhz) has a (theoretical) throughput-speed of 3200 MB/s. And to further confuse you: those new HT P4's (and Athlon Nforce2 motherboards) support "Dual-channel memory", which lets two DDR400 chips work together to act as a single chip with a throughput speed of (theoretically) 2*3200 = 6400 MB/s... |
09-07-2003, 03:38 AM | #5 (permalink) |
Knight of the Old Republic
Location: Winston-Salem, NC
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Yeah, I decided to not go into that and try to simplify it. But to add to the confusion, Athlon XP processors also have double FSB speeds. That's why you see 133 and 166 in BIOS instead of 266 and 333!
-Lasereth
__________________
"A Darwinian attacks his theory, seeking to find flaws. An ID believer defends his theory, seeking to conceal flaws." -Roger Ebert |
Tags |
ddr, ram, understand |
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