How important is it to get a CPU which matches my mobo's FSB?

[rodboev]

I ordered the GIGABYTE GA-P35-DS3L which supports 1333 MHz FSB and I'm trying to figure out how important it is that I get a CPU which also supports the 1333 MHz FSB. I understand that the higher FSB is needed for a quad core but I can't find any info on its importance in a dual core.

I'm more interested in getting quality components than break-neck speed but with that said, I was looking at the E6550 since it gives me 2.3GHz, 4mb L2 and a 1333 MHz FSB at $175. I don't want to waste the money if a $125 E4400 will do nearly as good a job. What would be the better option?

Also, what's the consensus on DDR2-800 vs. DDR2-1066: worth the price difference or not?

 

[ChronoReverse]

Matching your motherboard's FSB isn't important at all (and can even is detrimental to overclocking efforts... in an oblique way, don't take this as gospel).

DDR2-800 is more than enough for any stock performance as well as moderate overclocks.

 

[gwai lo]

The DS3L also supports chips running 1066 MHz and 800 MHz FSB. The higher FSB is not needed for a quad core, it just helps the processor in general really, as it allows more data to be delivered to the processor at once.

As for whether or not an E4400 will fulfill your needs, you're better off looking at reviews and benchmarks. What do you plan on doing with this system anyway?

As for DDR2-800 v. DDR2-1066, it just depends on how much you want to overclock. You can run a divider that runs your RAM faster than your FSB, but that doesn't really net all that much performance. Anyway, as for the overclocking, I'll take an E6550 as an example.

At stock speeds, an E6550 runs at 333 × 7 = 2331 MHz. Seven is the multiplier and 333 MHz is your FSB.
With DDR2-800, you can run it at 400 × 7 = 2800 MHz before having to overclock your RAM.
With DDR2-1066, you can run it at 533 × 7 = 3731 MHz before having to overclock your RAM.

The last one may be a bit difficult to obtain, but if you're aiming for really high clocks and have a solid cooling set up, then that's what you'd probably want ( you'd also probably want a processor with a higher multiplier ). Anyway, overclocking typically falls onto 1) whether your chip can pull that kind of speed 2) whether your RAM can pull that kind of speed 3) whether your cooling can hold up at that kind of speed 4) whether your motherboard can pull off that FSB. With faster RAM, you essentially eliminate one of these possible barriers.

 

[rodboev]

My work is more memory and I/O intensive than CPU intensive since I'm working with graphics most of the time. The most taxing would be video encoding or HD decoding, which I've looked at the benchmarks for and it seems to me as though the E6550 would be a worthy (e.g. is up to 30% faster at these tasks) upgrade from the E4400 for the 40% greater cost.

My main concern is longevity. My last system was a then-near-top of the line P4 2.2 GHz I purchased 6.5 years ago and lasted me that long. I'm looking for a similar sweet spot now, and I'm wondering if my % estimates above are mostly right and how the FSB matchup plays into the performance.

Thanks for all the help, I've been out of the game for a while and I appreciate the input.

 

[rodboev]

Ended up getting the E6420 OEM. Picked up some Arctic Cooling MX-2 Thermal Compound and looking for a heatsink/fan now, and I'll pick up 5-5-5-15 DDR2-800. Hoping for 375MHz FSB to get to 3 GHz on air. Thanks all.

 

[RussianSensation]

Originally posted by: rodboev
Ended up getting the E6420 OEM. Picked up some Arctic Cooling MX-2 Thermal Compound and looking for a heatsink/fan now, and I'll pick up 5-5-5-15 DDR2-800. Hoping for 375MHz FSB to get to 3 GHz on air. Thanks all.

Great. I have the same board exactly. Revision 1.0 with F4B bios hits 425FSB with +0.1 adjustment on northbridge and FSB link. It hits 389 FSB without any voltage adjustments to the motherboard. I did swap the stock northbridge with the one from DS3 965 motherboard.

For a heatsink this is great bang for the buck: $10 Cooler Master Eclipse

OR $20 THERMALRIGHT ULTRA-90 if you have a spare fan.

For ram, I recommend:
$59 OCZ Platinum Revision 2 DDR2 CL4
$55 OCZ Reaper CL4
OR
Patriot LLK CL 4 for $60

 

[rodboev]

Any non-rebate options on the RAM? I need 4 GB for my line of work and all these rebates are limited to 1 per product

 

[myocardia]

If you need 4GB of RAM, and you also have the intentions of overclocking, then you'll want to buy a 2x2 GB set, and not two 2x1 GB sets.

 

[rodboev]

I'm at 400FSB without any voltage changes. It seems to be booting and stress testing fine, and temps are as expected. Am I doing damage by not changing the voltage or would it not have started up?