Ddr3 ram

[2048Megabytes]

I noticed the price on DDR3 RAM has been dropping lately. Double Data Rate 2 memory seems to about half the price of DDR3 currently.

For instance this Patriot Extreme Performance 2GB DDR2 800 (PC2 6400) is $43:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220144

But this Patriot Extreme Performance 2GB (2 x 1GB) DDR3 1333 (PC3 10666) is $70:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220304

Opinions if DDR3 memory is still too expensive versus DDR2?

 

[Mez]

Yes DDR3 is still too exspencive vs the performance of DDR2. for 70$ you can get a set of 4GB of DDR2-800.

"future proofing" yourself with DDR3 is a complete waste. I say wait for the Nehalems so you can fully utilize the ability of DDR3. And plus, the Nehalems are going to be using completely different sockets than the C2D's, and the C2Q's.

 

[lovely?]

lol my ddr800 can do 1200mhz with 6-7-7-18 that ram does 1333mhz with 9-9-9-24. its definitely not worth the extra cost.

 

[2048Megabytes]

Thanks for the input so far.

I know DDR RAM transfers two bits per clock cycle and Double Data Rate 2 transfers four bits per clock cycle. So how many bits of data does DDR3 transfer per clock cycle?

 

[Cleric7x9]

4

 

[TrainTrackHack]

DDR means Dual Data Rate and it still performs two transfers per clock cycle, it doesn't matter whether it's DDR, DDR2 or DDR3.

 

[Cleric7x9]

DDR means Dual Data Rate and it still performs two transfers per clock cycle, it doesn't matter whether it's DDR, DDR2 or DDR3.

well, not really. also, its Double Data Rate lol

the difference between DDR1 and DDR2 is the prefetch. DDR1 uses a 2-bit prefetch on the I/O Buffer and DDR2 uses a 4-bit prefetch.

 

[2048Megabytes]

My computer books state DDR SDRAM stands for: Double Data Rate Synchronous Dynamic Random Access Memory (that sure is a mouthful of words).

Cleric7x9 is also correct concerning the transfer rates of DDR and DDR2.

DDR2 RAM should have been called Quad Data Rate RAM in my opinion.

 

[tyttebøvs]

hackapelite is right. Prefetch buffers are internal to the module. They have no saying in data transfer on the bus.

 

[TrainTrackHack]

the difference between DDR1 and DDR2 is the prefetch. DDR1 uses a 2-bit prefetch on the I/O Buffer and DDR2 uses a 4-bit prefetch.

Cleric7x9 is also correct concerning the transfer rates of DDR and DDR2.

Nope. As tytte said, prefetch buffers are internal; the external bus still transfers two bits per clock cycle. Doubling the prefetch buffers simply allows the internal modules to effectively double data throughput (with the cost of added latency); this was done so that the memory speed could be increased without actually increasing the clockspeed, because higher clockspeeds tend to cause certain problems (more power consumption, more heat, scaling difficulties,...)

 

[2048Megabytes]

Interesting. However this is one of the reasons I simply prefer to look at the PC rating on RAM. It simplifies everything.

When all numbers are said and done it is the amount of data transferred per second that really matters with RAM. (The PC rating is the amount of megabytes transferred per second).

I do have an understanding regarding RAM in dual channel mode. Since dual channel memory increases the data path from 64-bit to 128-bit it effectively doubles the data transfer rate of the RAM to the memory controller.

The above statement concerning dual channel RAM is correct isn't it?

 

[Cleric7x9]

it doubles the bus, and def helps speed things up, but it doesnt double the transfer rate, its not that much of an improvement

 

[2048Megabytes]

it doubles the bus, and def helps speed things up, but it doesnt double the transfer rate, its not that much of an improvement

What is the average boost of speed dual channel memory gives? About a 20% or 10% faster data transfer rate than memory in single channel mode?

 

[Cleric7x9]

i have never seen any benchmarks, but i would say its probably like 25-50%

 

[TrainTrackHack]

I do have an understanding regarding RAM in dual channel mode. Since dual channel memory increases the data path from 64-bit to 128-bit it effectively doubles the data transfer rate of the RAM to the memory controller.

The above statement concerning dual channel RAM is correct isn't it?

Not exactly... the transfer rate remains the same, but bus width is doubled. The throughput is effectively doubled.

What is the average boost of speed dual channel memory gives? About a 20% or 10% faster data transfer rate than memory in single channel mode?

Well, in theory memory performance should (almost) double, since dual-channel is not like SLI/Xfire where twice the cards doesn't equal twice the performance. However, since memory throughput is rarely the bottleneck, the performance increase in real-world applications is usually negligible, and depends on how memory-intensive the application is as well as the speed of your current RAM. Assuming you have DDR2-800 (in your sig) with decent timings, the performance increase in games is usually only a few FPS if even that, and in everyday stuff (music, movies, the net) you won't even see it. In heavy multimedia apps & encoding the performance gains may be (and probably are) more significant, but I doubt dual-channel would under any real-life circumstances increase performance more than, say, 20% tops.