DDR2 - Good or Bad?

[Doomulation]

So, maybe you've heard of the new memory that's soon to be hitting the market: DDR2. Those of you (most should) who know about DDR memory, well, this is a new generation of that memory - DDR2.
The DDR2 promises lower voltage and higher speeds. From 400 up to 800 MHz instead of the 200 to 400 MHz from the original DDR.
However, this has come with a cost, as well. The latency timings has gone up. Now, I know that most of you don't get a thing when I talk about latency timings, soooo... let's investigate this a little further.

Here's an intresting article I found: http://www.lostcircuits.com/memory/ddrii/
It explains how memory works and how latency timings works. It also explains how the DDR2 memory works.

After reading this article, the big question is... is the DDR2 good... or bad?

 

[vleespet]

speed = ok
temprature = bad. This will really require an extra cooler, but after that, it should be ok anyway (however, I doubt it if the speed would completely be doubled, we all remember the Matrox Parhelia, don't we )

 

[Shin_Gouki]

for me bad -> ok it is advanced over DDR "1" but only increasing clock speed
i would prefer XDR thing or such technoloiges which increase efficiency per clock, but unfortunlay these kind of technologies are no cheap
nor are the technologies which are needed to use it ( boards, chip set...)
see what happend to Rambus ,
DDR and 2 is quite cheap but not better...
but price is important on selling markets.. so
lets see how far this cooling fanaticism goes then...
wbr Shin Gouki

 

[Doomulation]

Errr the DDR2 runs at a lower voltage, namely 1.8V versus 2.5V, so it should be cooler and not draw as much power as its predecer.
And, believe it or not, the lower the latency timings, the faster the memory is. It will simply do more per clock cycle.

Have you guys even read the article?

 

[Clements]

Well, for example, a PC3200 DDR2 module would be no faster than a PC3200 DDR module, but would cost much more. But you probably knew that already.

 

[Nighty0]

CAS latency of 5??????? they're crazy???? i will continue with my rambus memory..... (if i will buy an Intel Processor again, coz today i prefer AMDs.......)

 

[sheik124]

my opinion, BAD, ddr2 in case you haven't noticed is back completely by Intel, it will flop like rambus did, or if not, will take a LONG time for acceptance. 512 MB DDR2 PC3200 modules are expected to cost 500 fucking dollars upon release. i'd rather buy 2 GB PC3200 DDR ram instead

 

[Eagle]

Not to mention Dual Channel DDR, while not technically faster in terms of memory speed, can make it seem faster. Much in the way the P4 uses its front side bus, Dual Channel DDR uses two sticks of ram to create the illusion of faster memory. But hey I dont care if its an illusion as long as it works. So really whats the point of paying that much for DDR2?

 

[Doomulation]

There was a little benchmark I found for latency vs. bandwidth. The results were most shocking.

AMD Athlon64 FX51 (henceforth called FX51), is one of the newest athlon processors, with high latency timings, but high bandwidth. There were P4 in the test as well. The P4 had hyper threading technology enabled and dual memory.
All do we know that athlons perform slightly better in games, but not in regular software, such as 3d studio max, for example. But that's beside it. In all the tests (in the games), the P4 fell behind the athlons, as thus I will not describe those here, because they're not intresting.

In the test also, they had an Athlon64 3400+, which they overclocked a little. The overclocking was stable, with no crashes, so they took it into the test, as well.
The shocking news was that in most games the Athlon64 3400+ overclocked (henceforth called 3500+), actually beat the FX51. The FX51 sometimes even fell behind the P4.

So that will give you a look into how important the timings are.
Will the DDR2 flopp? Nowadays, they mostly ignore the timing to get higher bandwith rates. It's a shame, really, because I for one, don't think I'll be upgrading memory anytime soon.

Just for the sake of it... bandwith vs latency, here are the results of when one is higher:
If the latency timings is higher (BAD!) and the bandwith is high, the result is that it can output much data at a constant flow, but it takes longer to push the data out of the memory.
If the timings are lower (this also means the bandwith is lower), the data is pushed out of the memory faster, but it cannot push out quite as much data as when having higher bandwidth.

Hence, lower latency timings means more instructions per clock cycle, and higher timings means less.

For your reference, here's the article: http://www.lostcircuits.com/cpu/amd_a643400

 

[sheik124]

1. athlon fx 53 is the king of the crop now
2. did they happen to run the FX51 in dual-channel? and the latency timings are ram dependent afaik

 

[Doomulation]

*Shrug* Quite sure it's for processors as well. Check the article for your reference, because I don't know much more.

 

[Nighty0]

DDRI isn't dead!!!!!!!
but latency times are a litle higher......
http://www.ocztechnology.com/products/memory/OCZ_EL_DDR_PC-4800_Dual_Channel

only tested on Intel I875 for now.......

 

[Doomulation]

3-4-4-8 is almost as bad as DDR2.

 

[The Khan Artist]

Question: Doesn't the Athlon FX use buffered ECC memory? That would explain the speed difference.

 

[Doomulation]

No idea
Besides, the FX fell back in most tests too. This is about the timings that matter.
What's this 'buffering' anyway?