Fast number crunching & Memory I/O - is AMD worth the wait?

joelbaby

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May 18, 2007
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Hi,

What is the best CPU/RAM combination for fast number crunching?
Is it worth holding out and waiting for the new AMD chips?
Is it worth waiting for DDR3?

I use software similar to Matlab. Lots of Floating Point calculations, and lots of communication between CPU and Memory. Multiple CPUs are not supported - so Quad Core is pointless.

Best bet now (I think): E6600 + 2Gb DDR2-800 low latency RAM.

One thing I don't understand about the memory is: If the FSB of E6600 is 1066MHz .. wouldn't 1066MHz memory provide the fastest match? I think that an Asus P5B deluxe mobo can be set to run at this speed.

However, considering that AMD are coming out with some dual cores using HyperTransport 3 later in the year - would it be worth holding out for them?

By the time AMD release these chips will Intel have any significant changes to their Dual core lineup?

I don't mind holding out a few months IF these new CPUs are going to be far better than what is available now for Floating Point and Memory performance. I don't want to regret my purchase just a few months down the track.


Joel
 
First, the golden rule of buying a computer is buy one when you need one. If you need it now, get it now. If you don't, then wait. There will ALWAYS be something new coming over the horizon.

First, is your program x87 or SSE floating-point? The X2s will beat the Core 2 at equivalent clock speeds in x87 FPU power while the Core 2s are significantly faster at SSE math.

If the program is not multithreaded, then either AMD or Intel's chips will work equally well as both are awash in bandwidth for one core to use. (The same holds true for two cores as well.)

You want DDR2-533 for that system as the aggregate bandwidth from CPU to memory controller is 8.5 GB/sec, so two sticks of DDR2-533 provide exactly that. DDR2-1066 provides that bandwidth in one stick, but no current Intel chipset can handle DDR2-1066 without overclocking or dropping the multiplier on the CPU.
 

joelbaby

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May 18, 2007
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Hi,

thanks for the replies guys.
It does seem odd that DDR2-533 is the answer :) but I'm not complaining.

My question has evolved into wanting to know what system mobo/cpu/ram will give me the highest bandwidth. That is a question for the memory forum.

Joel
 
The bandwidth doesn't vary much between systems. The 1066 MHz FSB of the E6000-series Core 2 Duos is more than enough for the two cores. Heck, the 800 MHz FSB of the Core 2 Duo E4000 series is enough, but I bet that you'd want something a little faster than the 2.0 GHz E4400. And about any chipset will provide roughly the same performance for the CPUs.

The Core 2 Duo E6700 is probably your best bet for a sub-$900 processor. It will be only a little bit slower than the fastest Athlon X2 (6000+) in x87 FPU but be quicker in SSE, and also run cooler as well. IIRC, the E6700 is about $360. If you don't want to spend that much, then I'd suggest the Athlon 64 X2 6000+ for $230 as its SSE performance is about equivalent to the $230 Core 2 Duo E6600 but its x87 FPU performance will be much better. The X2 6000+ does run a bit warmer than the E6600 does, if that is an issue.
 

vylo

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I got tired of waiting on AMD to catch up and went with Intel core 2 Quadro. Thing is smoking. Hopefully AMD catches up, because the competition is what makes both companies pump out worthwile products.
 

turpit

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What both MU and Vern said, however, remember you will be waiting for K10(new AMD) for awhile as the server versions wil be released first, the DTPC versions will not come until the following quarter. From Intel, there will be significant price cuts and updated Core 2 Duo processors coming (1333FSB) in July.

No one really knows how the new AMDs wil perform as there has been no 3rd party testing yet, and inconsistant clams from AMD. They may be the greatest CPUs ever to power a server or DTPC, then again, they may be AMDs netburst, so waiting for them may or may not be a winning gamble
 

Mondoman

Splendid
Hi,

thanks for the replies guys.
It does seem odd that DDR2-533 is the answer ...
That's assuming you're running the DIMMs in dual-channel mode, which interleaves addressing in 64-bit chunks to effectively double the memory bus bandwidth using a pair of 64-bit channels.
In single-channel mode, you're right that you would need to run at DDR2-1066 memory bus speed.