Got P4S533 Have Questions...New to Intel

I've been using AMD's for quite a while. I've decided to go with an Intel P4 1.8A for a machine my parents wanted built. I've got the P4S533 board and have a couple of questions:

1. What's the best memory/cpu ratio to use? That is something new to me. I'll be using Crucial PC2700 in a single 256MB stick.

2. What's up with the power supply connections? There is an extra molex connector on the board and is described as "Asus EZPlug. The Asus EZPlug power connector lets you use your existing power supply and eliminates the need to buy a special ATX 12V power supply to support your Pentium 4 CPU." I don't see anything in the manuals on this at first glance.

I'm upgrading the machine I last built for my parents about 4 years ago. It's an AMD K62-500 on an old Tyan board. The power supply is ATX and 300 watts, but being 4 years old, will I have issues?

Any help is appreciated.

1. For the CPU/Memory ratio, set it to 4:5 if you're overclocking to 133MHz FSB. If not, then set it to 3:5.
These two ratios will set your memory to run at PC2700 (166MHz, 333MHz DDR) speed.

2. You can plug a normal 4-pin molex into that EZPlug thingy. The EZPlug is for users who have PSUs that don't have the 2x2 ATX +12v molex.
You can try booting up the system with your old PSU. Go into the BIOS and under the PC Health monitoring, check the voltage lines and make sure they don't fall too low. If they do, then I guess it's time for a new PSU.

Many thanks for the quick response. I'll likely overclock this a tad, but nothing major. I might try for 2.2ghz or so. I got them a Thermalright AX-478 heatsink with Panaflow 40CFM 80mm fan so that should be pretty good cooling.

We'll see how it turns out. This will be the first Intel system I've built since they were using the Pentium 166.

Since you've got a good HSF and a decent 80mm fan, you should be able to go up to 133MHz easily. Overclock without increasing the Vcore first, and do so only if the system fails to boot at 2.4GHz or is unstable.

When the FSB is at 133MHz, must double-check that the CPU/PCI ratio is at 4:1.

Can you explain to me how the CPU/PCI ratio and CPU/MEMORY ratio's work?

you don't need to "double-check that the CPU/PCI ratio is at 4:1" with the fsb at 133mhz. at 133mhz, the pci frequency automatically is set to 33mhz by the bios on the p4s533, always - every time.

between 100mhz fsb and 132mhz fsb - the pci freq divisor is 3. divide your fsb by the pci divisor and you'll see your pci frequency - but, the bios on a p4s533 shows you this frequency right next to your fsb setting anyway. and you can see the pci frequency change from 44mhz pci at 132mhz fsb to 33mhz pci at 133mhz fsb. <--run on sentence ;o)

anyway, the pci frequency affects all pci card devices, some (if not all) onboard peripherals, hard drives, and agp video cards. as the pci frequency deviates further away from 33mhz - the more likely it is that some pci dependent device will malfunction due to being run out of spec.

because of this, you may have success running at 133mhz fsb when the pci divisor is 4 - but you may not have success running at 132mhz fsb when the pci divisor is 3.

some motherboards have pci/agp freq locking features that lock the freq to the 33mhz standard. the p4s533 does not have this feature.

as far as the pci/cpu ratio - you can't change it - it is determined by your FSB.

now, the cpu/mem ratio.

if your ratio is 3:5 you

divide your fsb (cpu) by 3 and take that quotient and

multiply by 5 - the end product is your memory clock frequency.

if you have ddr333 - the stock clock frequency is 166mhz - the ddr# is twice the memory frequency.

if you're running 100mhz fsb -
divide 100 by 3 = 33mhz

multiply 33.33mhz by 5 and your product is 166mhz = ddr333

as you increase your bus speed, you increase your memory speed

by now you should see that the ratio of 3:5 is the same as 100:166 (close to it anyway).

at 133mhz fsb - to run ddr333 you need the ratio 4:5.

if you want to run ddr400 you would select the ratio of 3:6 at an fsb of 100mhz. at an fsb of 133mhz, you'd select 4:6.

got it????

-BdK

Makes perfect sense now....thanks for the explanation BDK.

de nada

de nada bro - nothing i like better than participating in the overclockers.com forums while i'm gettin' paid time and a half!

;o)