building a desktop

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Been quite a few years since I've built a desktop -- got a few questions.  I
picked up an ASUS M4A87TD EVO motherboard and 2 sticks of Corsair ram (4 gig

The motherboard has 4 ram slots -- the first two slots are Channel A and
second two slots are channel B.  Should both sticks go into channel A or
should one stick go into channel A and one stick in channel B?

This motherboard has a 24 pin motherboard connection and I was thinking
maybe I should upgrade the power supply.  Whats a good value on a 24 pin
power supply with at least 650 watts?  Prefer active power correction if

Re: building a desktop

BenT wrote:
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with two sticks, use the first of a and the first of b.
That way (if the sticks are the same type/size) you get
a higher throughput on the memory bus, because access is

Re: building a desktop

BenT wrote:
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Actually, before you get too excited about Power Factor correction,
read some customer reviews for your power supply. There are some
supplies, which causes problems for the UPS they're connected to.
If the UPS is "true sine" or the like, then you can probably
connect anything you feel like. A UPS with something closer
to a square wave output, can cause problems with active PFC.
So be careful what you wish for.

This blog is one example of a user's experience. /

If your new PC has a low enough load, you may be able to use
an older 20 pin supply. If you know it'll be running massive
video cards (like a GTX 470 or 480 or the like), then
you might well be right in getting a bigger supply.
Generally speaking, the number of available PCI Express
power connectors, and the number of connectors required by
your video card(s), gives you some idea whether the old
power supply was meant for your new system or not.

"Using a 20 pin supply, on a 24 pin motherboard" - suitable
if you have only one PCI Express video card present in the system.
Some cards now, only draw 12V @ 2A from the video card slot,
which is why a 20 pin connector may be enough to get the job done.
I think a 6600 video card, was around 4 amps or so, still within
the 6 amp limit of a 20 pin connector (with its single 12V wire).

More examples of connector pictures here, if you need them.


This one has Active PFC and has >1000 customer reviews.


In a quick check, I'm not seeing complaints about operation with
respect to a UPS, so perhaps that one is OK.

Could the UPS type, cause damage to an active PFC power supply ?
That, I don't know. We'd need someone who was good at post
mortem analysis, to detect such an issue.


Re: building a desktop

On Fri, 21 May 2010 19:13:18 -0500, BenT

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The latter.

$40 AR for another week, 620W continuous compares to other
650W nominal rated PSU at least.

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