E8400/Q6600 with DDR-800?

[kosha]

I am planning on building a system to replace my Athlon XP 2600+ system that I've had for five years.

My planned system is:

Cheap motherboard
2x1gb DDR2-800
Intel Q6600 or E8400
Existing 300watt PSU
Existing 250gb ATA100 hard drive


I am wondering if I will be able to use the DDR2-800 with the E8400 or the Q6600 even though the E8400 has a FSB of 1333mhz which of course is much higher than the speed that DDR2-800 operates at. Will this mean that the FSB on the CPU will have to be lowered to match or is there some way to let the CPU operate at the 1333mhz FSB while the ram operates at the 400MHz x 2 multiplier?

 

[Markfw]

The 1333 uses DDR-667 ram (stock). The Q6600 uses DDR-533 (stock) for overclocking you need DDR2-800 for the Q6600, and at least DDR2-1066 for the E8400.

If you are overclocking
Target speed for the Q6600 would be 3.5-3.6 (up to 400 x 9)
Target speed for the E8400 is 4.0-4.2 (up to 533 x 9 or more)

 

[JustaGeek]

You will be able to use DDR2 800 with both processors, with the use of memory multipliers.

The "basic" FSB is 266MHz and 333MHz for Q6600 and E8400 respectively.

266MHz x 3/2 Memory Multiplier = 400MHz memory bus x 2 DDR = 800MHz memory speed.

333MHz x 6/5 memory Multiplier = 400MHz memory bus x 2 DDR = 800MHz memory speed.

Make sure that the motherboard you choose supports the adjustable memory dividers - it will most likely say "Supported Memory Speed DDR2 800".

 

[Anubis]

Originally posted by: Markfw900
, and at least DDR2-1066 for the E8400.

you dont need DDR2-1066 for the 8400
im runing 9x440 1:1 ratio on DDR 800 on my C2D 8400

 

[VirtualLarry]

You're going to need a better than 300W PSU for the Q6600. I don't know about the E8400, they take less power, but still take more power than stock when overclocked.

 

[Idontcare]

Originally posted by: VirtualLarry
You're going to need a better than 300W PSU for the Q6600. I don't know about the E8400, they take less power, but still take more power than stock when overclocked.

If there is no overclocking involved then I wouldn't be surprised if a 300W PSU holds a Q6600. The video card will likely make all the difference.

My Q6600 system (@3.3GHz) pulls 260W from the wall. That means the PSU is pusher something <260W to the system components after factoring in AC/DC conversion inefficiencies.

So a stock quad system, again video card will make all the difference, might consume 200W fully loaded.

There is no doubt other concerns the OP should have regarding their PSU, as rated Wattage tells you almost nothing about how it is distributed across the wires and how stable is the output when you go from idle to fully-loaded on the motherboard.

I would not buy a 300W PSU to power a stock Q6600 quad, but if I had the PSU already then I'd certainly press my luck and give it try to see if it works before purchasing a newer PSU without the data.

 

[Markfw]

Well, I did run a Q6600@3.5 on a fortron 450, but it had stability problems. I put a 550 in there, and its fine now. 1300le video card, so not much draw there. I don't think a 300 would work even at stock either.

As for running DDR800 @ 440, that quite OC'ed memory, and all I can say is YMMV. I can OC processors a lot, but most of my memory doesn;t OC well.

 

[Anubis]

Originally posted by: Markfw900
Well, I did run a Q6600@3.5 on a fortron 450, but it had stability problems. I put a 550 in there, and its fine now. 1300le video card, so not much draw there. I don't think a 300 would work even at stock either.

As for running DDR800 @ 440, that quite OC'ed memory, and all I can say is YMMV. I can OC processors a lot, but most of my memory doesn;t OC well.

look at this thread
http://forums.anandtech.com/me...=2145748&enterthread=y

most people are doing it with DDR800

 

[nyker96]

You probably want to get some OCable DDR800 for E8400 because that chip can do 4+. Get something good like Ballistix DDR800 that can do 1000+ can max that chip out. But for Q6600, probbaly normal DDR800 is enough.

 

[Vixx]

The price between DDR2-800 and DDR2-1066 is minimal, so it doesn't make sense to invest in a good system and skimp to save $15 for slower/cheaper memory.

The difference in memory speed CAN make a difference in overclockability. With DDR2-800 I hit a wall at 445 MHz FSB. With DDR2-1066 I can hit FSB speeds in excess of 515 MHz. The difference is $15. Is it worth it to you? The bigger the range of the FSB frequencies you have, the more room you have to change settings and find the sweet spot for your processor. Mine can do 450*9 like everyone else, but I also have the option to run 475*8.5 or 500*8, all at an actual vcore of 1.265v with a stock Intel HSF.

DDR2-800 may be ok for use with a Q6600 setup, but I still think that faster memory is worth the minimal difference in price.

If you want a fast AND stable system, you need to consider quality parts, ESPECIALLY if you're planning to overclock. Spend a little more for a good motherboard, memory and power supply to avoid instabilities. A quiality power supply is more important than rated/advertised watts. After you fry a couple of components due to cheap parts, you learn the value of quality components, especially if you plan to make this rig last for a while.