E6600/E6420/E6320 with PC-6400 ram?

Bytrix

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I've spent the last few weeks looking into the various options for overclocking these great new chips (my last 3 PCs have all been athlon based) and I had more or less decided on getting an E6600 ( and the Arctic Freezer 7 on an Abit AB-9 ).

But, I've been reading a few overclocking guides (mostly for the lesser models in the C2D line) which all state it's 'best' to set mem:cpu to 1:1. In the case of the E6600 assuming I wanted to get full speed (without overclock) from the ram this would mean setting the CPU FSB to 400mhz, which would result in the E6600 running 3.6ghz. I've not seen many reports of people running the chip at this speed.

I understand I will probably be able to get 333mhz FSB and run the ram at DDR2-666, but I was thinking surely the faster you can get your ram running the faster the system would be? So I have a question:

Taking the following three systems into consideration, clocking the CPUs to the same clock speed (3.2ghz for this example), would one be faster than the others? I'm just interested how much of a difference the FSB/RAM speed would make to the overall system speed:

System 1
FSB at 356
Core 2 Duo E6600 (9x356 = 3204)
Crucial Ballistix DDR2-800 4-4-4-12 (2x356 = 712)

System 2
FSB at 400
Core 2 Duo E6420 (8x400 = 3200)
Crucial Ballistix DDR2-800 4-4-4-12 (2x400 = 800)

System 3
FSB at 457
Core 2 Duo E6320 (7x457 = 3199)
Crucial Ballistix DDR2-800 4-4-4-12 (2x457 = 914)

Now I have no practical experience with these chips and I've only ever overclocked my ram slightly but I would imagine the E6420 system would be faster than the E6600 system eventhough the CPUs are set to the same clock speed surely the increased frequency of the ram will help? But the opposite might be the case for the E6320 system as the ram would need to be overclocked and timings relaxed to reach 914mhz on 800mhz ram.

So... after that rather long (and my first) post,

1: Could I get 3.6ghz with an E6600, 400mhz FSB with Arctic Freezer 7?
2: If not, should I go with the E6420 over the E6600 to get the 400mhz fsb.

and 3: am I completely wrong about the affect on overall system speed from the memory frequency? I could be wrong, but it seems like it would be better to run the memory faster.

Thanks for any help and opinions, I'm hoping to order my bits this weekend and look forward to seeing how hard I can push a C2D (without spending a fortune).
 

skyguy

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1) No.
2) Yes, all things being equal
3) Not really. Again, all things being equal the faster RAM speed will result in faster performance. HOWEVER, the performance difference is very, very minor. You won't notice it real-world applications. It's mostly about the CPU clock speed. The C2D chips LOVE, LOVE high clocks.....thrive on it. Faster RAM speeds help, but not nearly as much.

Overall though, I'm really liking Option #2.
 

proof

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Yes, it is genrally much better to run your FSB:RAM in 1:1. I run mine in sync mode with the lowest possible timings. This gives me less latency and is just as good, if not better, than just a high frequency. My RAM is at 533 I think with 3-3-3-10 1T timings. I am trying out 2-2-2-8 1T but no luck.

Worked:
5-5-5-15 2T
4-4-4-12 2T
3-3-3-10 1T
3-3-3-9 1T
2-3-3-10 1T

Trying:
2-2-2-9 1T
2-2-2-8 1T
 

chief5286

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Based solely on reading these forums, I'd say it IS possible to get to 3.6 Ghz with a decent cooler. BUT, you'd probably need to get lucky to do so.


Like the above poster said, it is better to run your ram at a 1:1 ratio, but the difference is small. I think you'd be better off trying to hit the highest stable CPU frequency with decent ram settings than sacrificing CPU clocks for increased memory performance.
 

MacMan

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The e6600 is cheap enough that I would probably get that processor. The multiplier is unlocked down so you could always drop it a notch in favor of a higher FSB. (eg run at x8 instead of x9) The e6600 does have that x9 multiplier available though and leaves you the option of trying it to see which yields the best results.
 

Bytrix

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Yeah that's what I was thinking. I'm not sure though, I could get an E6420 and spend the money saved on one of the larger coolers (not much concrete information around the net on how well all the coolers compare with eachother). Zalman and Thermalright's offerings look good but so does the Arctic Freezer 7 which is under half the price.

I'm thinking of getting the E6420, and just found a site today selling 2x1Gb GEIL DDR2-800 4-4-4-12 ram for £58! so I might even get 4Gb.
 

proof

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Air Cooling Hest Sinks:
1) Thermalright Ultra 120 eXteme
2) Tuniq Tower 120
3) Thermalright Ultra 120
4) Scythe Infinity
5) Noctua NH-U12F
6) Zalman 9700NT
7) Thermaltake Big Typhoon
8 ) Arctic Cooling Freezer 7 Pro
And the future champion) Thermalright Inferno Fire eXtinguisher ICFX-14

Once again, I have to preach that 1:1 with lower timings is still better than just a high frequency especially with AMD platforms. And I would absolutely go with the Ultra 120 eXtreme. It is well worth the price.
 

Bytrix

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Thanks, I might get one of those. Keeping the CPU/system cool is very important to me as the PC room can get quite hot in the summer especially with my current setup with two overclocked athlon PCs, always had to drop my overclocks in the summer because they get so hot. I'd rather try and avoid having to do that this summer.