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DDR vs. DDRII: Fight!

Started by: Yuri | Date 05/20/04

Comments: 36 | Last Comment: 06/23/07

[1-20 | 21-30]

1. "Well, DDR2 has something it can be boastful of. The DDR2 core will work at 1.8v – compare to 2.5-2.6v of the current DDR (higher voltage means more heat, too). Thus, DDR2 should produce less heat. They estimate a reduction by 30% and practice will prove that."

While this is true, I can't help but point out that this makes little difference. Quoting DigiTimes/DRAMeXchange:

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Insignificant power saving

Memory system typically consumes about 10% power of a PC. If DDR2 reduces power voltage from 2.5V to 1.8V, it only saves about 3% power consumption in a PC. For notebooks, DRAMeXchange believes DDR2 will have less contribution in power saving than Intel’s Centrino CPUs.
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Not just that, but DDR-I already works at 1.8V internally. While the fact that heat is generated by the conversion process is a valid observation, it has already been established that current DDR-I modules are not limited by heat anyway. (Try actively cooling your memory -- you won't see much, if any, increase in overclockability of the memory speed.)

DDR-II's biggest problem lies in the socket change from 184 to 240 pins. Not only that, but two of DDR-II's biggest advantages touted by the industry, ODT and the use of BGA packaging for the chips, can be employed on DDR-I modules also. Regardless of that fact even, BGA packaging makes little difference to the speed chips are able to attain, but do increase production costs. In a market where competition is extremely fierce, this doesn't go down too well.

Kingmax is actually a good example of the fact we don't really need BGA: their BGA-based DDR400 modules used to be much less overclockable than Corsair or Mushkin's TSOP-based modules. Don't know how much their new modules have changed the playing field, but I haven't seen Kingmax modules far surpassing TSOP-based ones in speed yet.

So the only advantages DDR-II really holds over DDR-I are ODC, AL and higher speeds (but which won't make a difference until at least DDR2-667). The disadvantages are incompatibility with DDR-I sockets, higher cost and lower overall speed at "low" memory clocks.

Especially considering DDR600 is even being sold already (upper end of the market) and DDR500 is available from numerous vendors (mid-upper end), it doesn't seem like there is any need for DDR-II at all right now. The only problem being, of course, that Intel, AMD or JEDEC don't support it yet.

The only real problem I can see with DDR500 would be that the huge load it introduces on the mainboard over DDR400 would cause you to only be able to supply it with two, or maybe even one module (in the latter case, its speed benefit would get completely lost in a dual-channel setup). Unless the mainboard is able to supply the DIMMs with more juice (for example, with a connector like Shuttle's boards had).

Still, I don't know how well DDR-II addresses this problem over DDR-I. Could be that DDR2-533 suffers from the same issue.

[Posted by: Yuri | Date: 05/20/04]

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