Effect of FSB/mem latencie on C2Q

ZuePhok · 7th May 2007, 11:10 AM

did a few round of benchie lately.
what do you guys think?

Why spend more on high-performance RAM? doesn't improve the performance that much. Low latencies have little impact on the Core architecture. very diff from the K8/X2

Chai · 7th May 2007, 11:26 AM

This is the exact topic that we have been discussing in the IRC. While theoratically, the memory bandwidth is higher, in real world situation, it hardly makes any difference. For me, getting a DDR2-1000 memory is solely for overclocking purposes when reaching 500MHz with 1:1.

Maybe some other benchmarks will show a bigger difference?

ZuePhok · 7th May 2007, 12:08 PM

Quote:

Originally Posted by Chai

This is the exact topic that we have been discussing in the IRC. While theoratically, the memory bandwidth is higher, in real world situation, it hardly makes any difference. For me, getting a DDR2-1000 memory is solely for overclocking purposes when reaching 500MHz with 1:1.

Maybe some other benchmarks will show a bigger difference?

the smart prefetch and caching system in the Core die is doing excellent job in hiding mem latencies, reducing the impact on performance..i supposed.

I cant run more benchies at the moment. am stuck with other stuff..

here is another one. missed it this morning.
1333FSB, 4-4-4-12. 1T for 667 and 800, 2T for 1066.

as u can see, increased FSB doesnt improve the performance much as well. mem isnt the bottleneck.

Adrian Wong · 12th May 2007, 05:54 AM

Hmm.. Were you testing with a 2MB cached C2D or a 4MB cached one?

Chai · 12th May 2007, 09:37 AM

C2Q only has 4MB cache version, isn't it?

peaz · 12th May 2007, 10:02 AM

Quote:

Originally Posted by Chai

C2Q only has 4MB cache version, isn't it?

Yup. I think so too.

ZuePhok · 12th May 2007, 12:29 PM

4mb. i used C2Q because it's "supposedly" more bandwidth demanding.
but then again, higher bandwidth/lower latency do not help much. i supposed desktop app just isn't enough to stress the quad, or the prefetcher and caching system of the Core arch. is doing a damn good job.

neverthar · 14th May 2007, 06:49 PM

generally nowadays, it's not latency's that matter as archetecturally, C2D is not bandwidth hungry. It's more to cache hungry rather more then anything else. That's why we're seeing better gains scaling FSB using loose timings compared to tighter timings but lower FSB's.

I think anand and THG did cover this when C2D was launched or something. And anyway, since DDR2 runs at 4 bits per cycle, you actually have greater data transfer I/O's compared to DDR (2 bit), so the losses in timing latency's is negated already

ZuePhok · 20th May 2007, 11:53 PM

actually scaling FSB doesn't help much as well.

Chai · 28th Jun 2007, 08:37 AM

Sorry for digging this up again, but what about the new E6750? I haven't got the time to read reviews yet.

7th May 2007, 11:26 AM	#2 (permalink)
Chai Administrator Join Date: 6 Oct 2002 Location: Maranello Posts: 28,114 Reputation: 4649 Rep Power: 82	This is the exact topic that we have been discussing in the IRC. While theoratically, the memory bandwidth is higher, in real world situation, it hardly makes any difference. For me, getting a DDR2-1000 memory is solely for overclocking purposes when reaching 500MHz with 1:1. Maybe some other benchmarks will show a bigger difference? __________________ Chai (Contributor & Forum Admin) http://www.techarp.com/

12th May 2007, 05:54 AM	#4 (permalink)
Adrian Wong Da Boss Join Date: 10 Oct 2002 Location: In front of my ASUS F8V notebook! Posts: 33,103 Reputation: 3730 Rep Power: 78	Hmm.. Were you testing with a 2MB cached C2D or a 4MB cached one? __________________ Dr. Adrian Wong Tech ARP \| Blog @ Tech ARP \| The Free Trade Zone DYKT : The only offshore account I have is at the sand bank? We need PROGRAMMERS and TECHNICAL WRITERS! Contact us if you are a hot shot programmer or technical writer! My items for sale : 50x SD Card \| Memory Stick PRO \| Cyclone Energy Saver \| Seiko SS watch \| Tiger/Carlsberg beer jugs \| Travel Speakers \| Motorola V600 \| Nokia N90 SOLD! \| New Lowepro Mini Trekker AW Other items for sale @ the FTZ : Zalman CNPS9500 LED @ $20 \| Zalman CNPS7700 Cu @ $20 \| Zalman CNPS7000 Cu @ $20 \| Swarovski bracelet watches \| Dell 17" LCD \| Hi-Fi speakers \| English DIVX movies \| HP LaserJet toners! \| Office chairs

12th May 2007, 09:37 AM	#5 (permalink)
Chai Administrator Join Date: 6 Oct 2002 Location: Maranello Posts: 28,114 Reputation: 4649 Rep Power: 82	C2Q only has 4MB cache version, isn't it? __________________ Chai (Contributor & Forum Admin) http://www.techarp.com/

12th May 2007, 12:29 PM	#7 (permalink)
ZuePhok Hold me back! I can't stop posting!!! Join Date: 16 Dec 2002 Location: Floating Island Of Mandango Posts: 8,805 Reputation: 3294 Rep Power: 48	4mb. i used C2Q because it's "supposedly" more bandwidth demanding. but then again, higher bandwidth/lower latency do not help much. i supposed desktop app just isn't enough to stress the quad, or the prefetcher and caching system of the Core arch. is doing a damn good job. __________________ my motto: poison first, think later.

14th May 2007, 06:49 PM	#8 (permalink)
neverthar I'm a regular Join Date: 17 Oct 2006 Posts: 284 Reputation: 234 Rep Power: 6	generally nowadays, it's not latency's that matter as archetecturally, C2D is not bandwidth hungry. It's more to cache hungry rather more then anything else. That's why we're seeing better gains scaling FSB using loose timings compared to tighter timings but lower FSB's. I think anand and THG did cover this when C2D was launched or something. And anyway, since DDR2 runs at 4 bits per cycle, you actually have greater data transfer I/O's compared to DDR (2 bit), so the losses in timing latency's is negated already __________________ Only available by PM. Will help if possible Wanted: 2nd hand good condition IS lense for Canon 400D

20th May 2007, 11:53 PM	#9 (permalink)
ZuePhok Hold me back! I can't stop posting!!! Join Date: 16 Dec 2002 Location: Floating Island Of Mandango Posts: 8,805 Reputation: 3294 Rep Power: 48	actually scaling FSB doesn't help much as well. __________________ my motto: poison first, think later.

28th Jun 2007, 08:37 AM	#10 (permalink)
Chai Administrator Join Date: 6 Oct 2002 Location: Maranello Posts: 28,114 Reputation: 4649 Rep Power: 82	Sorry for digging this up again, but what about the new E6750? I haven't got the time to read reviews yet. __________________ Chai (Contributor & Forum Admin) http://www.techarp.com/

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