Mainly looking for PSU guidance

[LeftyAce]

Hi all,

I realize that this forum sees a lot of "How's my new PC" posts, but here's another. I'm mainly concerned about the PSU; is it quality (I think it's been recommended around here quite a bit) but more than that, is it powerful enough?

CPU: C2D e6600
MOBO: Asus P5B
RAM: 2GB Corsair VS DDR2 667
GPU: eVga geForce 7950
Optical: Lite On SATA DVD burner
HDD: 160GB Seagate 7200.10
Case: Enermax Chakra
PSU: Corsair 520HX
OS: Windows XP Home OEM
Monitor: Acer 17''

The guy I'm building it for has had a mac in the past, but says that's the only reason he hasn't been gaming; he wants to be able to play FPSs and WoW (which isn't really a hardware issue).. The budget is "as close to 1200 as possible," but he's willing to go a little over. The parts listed come to $1300.

Also, this build is precipitated by his mac dying, and as he's at school he's unable to wait for the April 22 price drop.

Any compatibiliity/reliability issues you can see?
How does the PSU look? And how do you calculate/decide how much power a rig is going to need?

Thanks for your time.

[Cricket]

That Corsair PSU should be fine.

Cricket

[freakitchen]

Concur with that.

Have you considered going the 'placeholder' option on the video card, rather than spending big bucks on a DX9 card? Will your customer want the option of DX10?

[LeftyAce]

Thanks for the verification on the PSU.

I suggested the placeholder option, but he would rather not have to mess with the computer at a later date, and isn't an "extreme" gamer. His timeframe for a serious video card upgrade is more than a year from now, and I figured at that point, the landscape will be enough different that he's better off getting a PSU and video card that will service him well now, and dealing with the cards and power requirements that are prevalent when he's ready for the upgrade.

[freakitchen]

They sound like decent enough reasons

If you're spending that much, aren't the 8800 series cards nearly within reach? The cheapest 8800GTS is only around $20-$30 more than the 7950 you chose, after rebate.

If you're looking to spend less, not more, then maybe consider an ATI X1950 Pro? This particular one....

http://www.newegg.com/Product/Produc...82E16814131030

...is cheaper than the nVidia, and I'm tempted to say will perform as well, if not better. On Tom's hardware charts, I compared the card you chose, to a 256MB version of the x1950Pro (no 512 version has been benchmarked), and the scores were very similar.

http://www.tomshardware.co.uk/graphi...=607&chart=196

Some options for you to think about

[LeftyAce]

Since we're over budget as it is, he's going to switch to the X1950 Pro. Thanks for the suggestion; I always go with nVidia for my own builds, but only because of their linux driver support....he's not concerned about that :-)

Just for my own edification, how do you guys calculate/judge/divine the power requirements for a given configuration? That's the part of part selection/computer building I don't have any idea about.


Thanks for the input. Should be ordering withing the next day. (Read: I'll be posting stupid problems in four days...).

[ZeratulsAvenger]

From the General Hardware forum I found a link to JourneySystems that allows you to configure a system with your components and find a rough estimate for the PSU requirements, but from the Power Supply FAQ:

Originally Posted by Tin Most people go by the wattage rating that is advertised somewhere on the power supply itself. Thats all it is everybody, just a rating. Most of the power supplies on the market today are rated at their peak output, which means it puts out that much power when its begging for mercy....ready to take your rig with it. Wattage means absolutely nothing. Heck, a hair dryer puts out 1200W, do you think it could power your computer? Think of a cheap 600W amplifier, but put it up against a quality 400W and it gets killed. Quality is what we're after everybody. Now that we know what wattage doesn't matter, so what really does matter? The amperage rating is the most important factor when choosing a power supply. Most modern Intel and AMD systems should have the +12V rail putting out 16a or more. If you look at the label on your power supply, you will see a chart showing the +12V, +5V, and +3.3V rails and how many amps each rail puts out. Many of the newer 6800 and X800 video cards run off of the +5V rail, and will need many amps to back it up. 30a on the +5V rail should be the minimum if you want to run the latest hardware, 40a preferably. The +3.3V rail supplies power to components such as your memory. +3.3V rail should be atleast 25a, 35a preferred though. Running your memory at 3.1V will eat up alot of juice, but think how much more you're using up when you add more modules. Most overclockers usually run atleast a 400W power supply. Once you start adding voltage to various components, its taking more juice to get it to run properly.

Basically, as long as you get a PSU from a reputable/quality manufacturer, you should be fine. That is not to say that running a quad-core system with dual video cards can/should still be run off of a 350W Antec PSU, but when dealing with the quality PSU's, a midrange PSU(in terms of watts) will do for most systems just fine.

EDIT:

Oh ya, and this Power Supply Reference Thread lists some of the well known and trusted PSU manufacturers alongside the more shady PSU's. While it hasn't been updated in awhile, I doubt as if the top-dogs have changed much, so your Corsair PSU is a fine choice.

[freakitchen]

Tin's comments are totally correct, there - but things have moved on since then. The +5v power rail had to be beefy in the days of AGP video cards, but today, it's all about the +12v rail - usually now split into two, three or more; because a lot of components require it. When I suggest PSUs, I do so based mostly on the video card. I'd look at 450w minimum for a system that includes a powerful card, and would always push that to a 500w+ unit when suggesting one.

Any system using a mid-range card, I'd suggest a decent 450w unit for; and I'd also suggest 450w for someone who's building a system with on-board video, but plans on upgrading to a dedicated video card. For an office system with on-board video that won't be upgraded, I have no problem suggesting 350w or less.

[Mr.Ferrari]

Also keep in mind..with DX10 cards being such power hogs...there is an imbalance of power draw when coupled with dual rail powersupplies. A average conroe system takes up very little juice. And when you have a single rail just dedicated to your processor/motherboard, there is going to be very little power draw. But the second rail, which is usually dedicated to the GPU, such as an 8800GTX, will nearly draw all if not exceed the limits of the 12v rail.

Especially in the future, when dx10 games come out, and 100% of the GPU of such powerful cards is being used.

Thats why we see manufacturers moving to tri rail or single rail powersupplies.

[freakitchen]

Mr F, I can appreciate what you're saying about the dual rail PSUs, but can you explain to me how a triple-rail PSU solves this problem? Are you saying that two of the three rails on, say, the Truepower Trios, are dedicated to video?

[Mr.Ferrari]

No prob, what I was trying to say is, that on new DX10 cards such as the 8800GTX, are equipped with two PCI-E connectors. Each of those PCI-E connectors are on its own rail in a tri-rail psu. So if each rail has 16a, the card has a available 32amps to draw from.

So it no longer has a 16a limit.

Future ATI cards will use such a dual connector design as well.

-Sorry for the confusion.

[freakitchen]

Not at all, thanks for the explanation

[LeftyAce]

Ok, the parts arrived, and I'm trying the out of case minimum parts build.

Got into the bios, and see that the CPU temp is 48 degrees C and climbing slowly to 50.5, at which point I turned off the machine. Was also getting slight video artifacting. I think I am going to remove the heatsink, clean it off, and apply AS, as there was some shifting around as I applied the heatsink the first time. Beyond that, could high-ish cpu temp's cause such artifacts?

I connected the 4 pin auxillary power connecter, and the PSU has an 8 (or 10?) pin aux connector that the motherboard doesn't seem to have a slot for.

Thanks in advance!

[Mr.Ferrari]

Yeah..thats probably the 8pin EPS connector. Some motherboards will have this 8pin slot, and others will just have a 4pin ATX .

[doubledragon5]

Some of the psu with the eight can be split into two 4 pins.. My Thermaltake 650W had a single 8 that was designed to be split in to the two 4pins...

[LeftyAce]

The computer boots fine (And installed windows) so I think it's an optional/auxilary connector.

My main concern is the CPU temp; it levels out at a little over 50 degrees C, and that seems a little high for a C2D. Anyone else have an idea what's normal? I know 60 degrees is the warning threshold, but I know people whose C2Ds run in the 20s.

[LeftyAce]

Sorry for double posting, but more info and an additional question.

I am running two instances of Super Pi (to stress both cores) and the CPU temp (As measured by ASUS PcProbe) hovers just below 60 (58 to 59, with occasional half-second dips down to 50 or 51). Speedfan shows a CPU temp in agreement with PCProbe, and two separate core temperatures, both in the low 40s. What's that about? And does it matter? Sorry for the incessant questions; it's my first build for someone else and I don't want anything to happen to his parts/$$ :-)

*EDIT* CPUz shows no throttling

[Mr.Ferrari]

CoreTemp can be a better alternitive for measurements. However 60c loaded is right where it should be for a C2D with stock cooling.

Your motherboard also might be utilizing Q-Fan controls, which throttle the fan down or up in order to maintain a certain temp. For quiet operation. It can be disabled if you so wish.

And does your case have atleast one fan in the back?

[LeftyAce]

Downloaded and ran CoreTemp. At idle, it lists each core as running below 30 degrees (28 and 27), and tJunction temperature as 85 degrees C!! PcProbe says "cpu: 44 degrees C"

What's the deal with the tJunction? I assume this isn't a problem, as the machine runs fine....

There's no rear exhaust fan, but there's a 25 cm side intake fan.....(yeah, it's huuuuge). The case said it came with a rear exhaust....going digging through boxes to find it...)

[Mr.Ferrari]

Tjunction is supposed to be the maximum temperature before shutdown. Don't worry. It will stay at a constant 85c. I should've probably warned ya bout that.

Pay attention to the two core readings.

The 28c and 27c are great temps.

[LeftyAce]

Don't worry. It will stay at a constant 85c. I should've probably warned ya bout that.

No problem, my heart surgeon thanks you for the added business.

But seriously, thanks for the clarification, seems like all is well with the build.