DDR questions

[blackhades]

From this article: http://www.anandtech.com/chipsets/showdoc.html?i=1535&p=6
It seems that dual channel ddr isn't really that effective compared to other single channel ddr chipsets in terms of performence, and dual channel ddr is only good when IGP is enabled. Is that really true?

Also, another question regarding ddr is that I saw on Newegg website, some of the ddr they sell have spec. such as CAS2-unbuffered. What does that unbuffered mean? Does that make any difference in terms of performence?

http://www.anandtech.com/chipsets/showdoc.html?i=1654&p=3
This seems to me that the performence is currently limited by Athlon XP's fsb, not the bandwidth of memory. If that is true, then would DDR400 improve much at all? From my understanding, it seems that kt333 chipset doesn't really a much better performence when compared to kt266a chipset. I think that may support the idea of cpu's fsb affects more than the bandwidth of memory and that cpu's fsb is the bottleneck not the bandwidth of memory. Can someone educates me here and tell me if that is true or not.
Thanks to all!

 

[bum_jcrules]

Before you or anyone else goes any further...

<A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=52029#52029" target="_new">Read this</A>

It will totally explain why the yields on a dual channel DDR system with an AMD processor are not yielding greater results.


As for Buffered, Unbuffered, Parity, ECC, Non-parity, etc. Start with <A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=38126#38126" target="_new">this</A>. It is a thread where I explained this.

<b>"If I melt dry ice in a bathtub, can I take a bath without getting wet?" - Steven Wright</b>

 

[blackhades]

Thanks a lot! I now understand better...Now it seems to me that nforce2 isn't all that promising in terms of performence.I thought dual channel ddr400 support sounds really good, but now it seems to be useless unless IGP is enabled...

This is probably the wrong place to ask this question, but I also would like to know about the future plans of both Intel and AMD...
From what I've heard so far, AMD will have Barton after T-brd, and Hammer after Barton. (Correct me if I'm wrong) What are the spec. of them? FSB? Any changes to cache? It seems to me that T-bred can be used on current XP motherboards, but what about Barton? T-bred seems like it's just an XP but smaller. Therefore it has different power regulations. Otherwise, everything else is the same (or seems to be the same. Again, correct me if I'm wrong!) What about Barton? What are the differences between Barton and T-bred and T-bred and XP?

What about Intel? I hardly find anything regarding Intel's future processors in this forum. Can anyone help me or provide me a link?
Thanks a lot!

 

[Crashman]

Let's K.I.S.S (keep it simple...). Anyway, the Athlon only has a max of 2.1GB/s on it's CPU bus to the Northbridge, so having twice that on the RAM side isn't going to do much. If you put your garden hose in a lake, it's not going to fill it very well!

But more importantly, Dual Channel DDR WILL help the P4. So your first sentence could really be misleading for newbies. This is because the P4 CPU bus has twice the bandwidth of the Athlon CPU bus. So while single channel is adequate for the Athlon, it is not adequate for the P4.

The perfect solution in terms of Athlon performance would be to drop the multiplier and raise the bus speed.

<font color=blue>By now you're probably wishing you had ask more questions first!</font color=blue>

 

[blackhades]

Thanks a lot! I already stated that I'm not sure about those things and that was why I posted them for help. I hope no one gets mislead by my post...
How is it possible to tune down multiplier and up the fsb?
I never tried overcloking but knowing about more things isn't a bad thing. :tongue:

 

[Crashman]

Well, if you look around the CPU's Overclocking forum, you'll find lots of guys talking about unlocking the multiplier. As for the highest bus speed you can get with the CPU, well, that depends on the chipset and board, particularly how much speed the chipset can handle, and what the lowest memory ratio is (and what kind of memory you're using). For example, if you could set your bus speed at 200MHz and your memory at 1/2 the bus speed, on a dual channel bus you would be able to use PC1600 and get the same results as others using PC3200 at a 1:1 ratio on a single channel bus...in theory. In actuallity there'a lot more to it.

Anyway, I would hope the nForce makes the 4:3 FSB/RAM ratio available. Because then you could increase your bus speed to 221MHz and run your memory at DDR333 speed, and you'd be using the dual channels to take up the difference in bandwidth. As to whether the chipset can handle that speed, who knows, probably not the integrated graphics versions. And the board manufacturer would need to use an appropriate clock multiplier. And the traces on the board would have to be properly shielded.

<font color=blue>By now you're probably wishing you had ask more questions first!</font color=blue>