Recommended PSU for 8800 series and higher...

[ParkerLewis]

Originally Posted by Juppy

Will my 450 Watts PSU do if I buy 2 more sticks of RAM and a 8800GT? Or should I get a 500Watts PSU?

If your PSU is from a quality brand, there should absolutely be no problem. Make sure you're buying a 8800 GT 512 MB : those are newer than the 320 & 640 ones, and need less power while being just as powerful (if not more).

Edit : a website to bookmark : eXtreme Power Supply Calculator Lite v2.5

[Fadingz]

Originally Posted by ParkerLewis

If your PSU is from a quality brand, there should absolutely be no problem. Make sure you're buying a 8800 GT 512 MB : those are newer than the 320 & 640 ones, and need less power while being just as powerful (if not more).

Edit : a website to bookmark : eXtreme Power Supply Calculator Lite v2.5

Cool site :O
I calculated using my set up, and I got it right on th 850 mark O..O

[silent-circuit]

PSU calculators generally aren't very accurate. All the current ones are using really old 'algorithms' to determine the required output and don't focus on the 12v rail, which has become more or less supremely important in modern systems... hence the massively overblown recommendation for Fadingz's machine, which would be fine with a quality 550 or 650 watt unit.

[runawayprisoner]

Well, the 12v rail thing differs from brand to brand. The only way to know the difference is to try everything out.

[james.miller]

Originally Posted by Squall-Leonhart

I will correct that sentence for you



The reason i use the word systems, is because it is the overall system that requires the power, in reality the video card only needs about 5-10amps..

correct with the theory, but your numbers are wrong. a single 8800 will require anywhere from 7 to 15amps or so at stock speeds depending on the card. an 8800 gtx ultra being the most power hungry single gpu card.a regular 8800gtx will use about 170w at stock, putting it right around 14amps.

And most psu's are split rail these days so 18a on each rail is good to have.

personally i prefer the Thermaltake toughpower range, the 600+ have 4 12v rails

they arent, actually. at least not in the power range you are talking about. most of them have single 12v rails like my corsair HX620, which is easily the best psu in its class.

Originally Posted by cid highwind

Well be glad about it.... Because if you use only half the power, your efficiency goes down as well. Usually between 70 and 90% of your max output the efficiency is best. So you just got an overpowered PSU that doesn't fit your needs, so you'll end up using more power than needed.

we're talking about a couple of percent at the most here. these days psu's are capable of >80% efficiency right from 20% output up to 100%. it used to be the case where psu's were very poor at low outputs, and still is with some cheap (nasty) brands. but a quality psu will not have that problem

these links are for anybody who needs to know more about psu efficiency.:
Overclock3D.Net :: Review :: Corsair HX620 620w Modular PSU :: Testing 200w load - 80% efficient. 646w load - 83.4% efficient.
JonnyGURU.com - Power Supply Reviews and more! - Reviews - Corsair HX520W 520W 252w load - 82% efficient, 522w load - 81% efficiant
Corsair HX620W Power Supply Review | Hardware Secrets 128w load - 85.9% efficient. 618w load 82.9% efficient.

i left this one for last. get this: 746w load - 82.6% efficiant : Corsair HX620W Power Supply Review | Hardware Secrets (cont., extreme load test) thats a 620w HX pulling 900w from the mains lol

so, this practice of recommending a psu in the power range for the job is futile. get the best built psu you can for your money and in that case, a 5 year garanteed corsair HX is the best of the bunch. it'll handle sli 8800gtx's, in fact it'll handle anything outside of a 9800gx2 quad setup im sure.


one more thing - psu calculators are trash as well. avoid them.

[Phil]

Yeah that is common a less wattage PSU beating a supposedly higher wattege PSU.

heres a review of my 650w toughpower taking down a 700w FSP FX70 Epsilon PSU

Mini Roundup: FSP FX700-GLN Epsilon & Thermaltake Toughpower 650W

[Cid Highwind]

Originally Posted by Squall-Leonhart

I don't believe thats correct Cid, a PSU will only draw as much power as the system needs.

Infact i've seen evidence on the contrary during experiments with electricity during high school, The PSU will only draw as much power as the system needs from the socket, so you aren't always drawing 700w from the socket with a 700w psu, Infact, modern day appliances indicate this, look at a tv on standbye for instance, Does it draw the same amount as it would when turned on? Not that i've seen.

I know it won't draw the maximum, however the overall effectiveness of a PSU, and thus the amount of power wasted or turned into heat differs based on the total % of its maximum capacity it needs. It's pretty much a general rule about PSU's efficiency. There's a certain sweet spot, so while I completely agree with you on your above points, I think there's more to investigate and that if going for a new PSU looking for something <600W would be best. Getting a solid brand that is known for its high efficiency would be the wise thing to do.

Besides, I really don't understand what's with all those high end 700+ W PSUs. CPUs have become more energy efficient over the years, a C2Q uses less than a Prescott, let alone a nice Conroe or Wolfdale processor. DDR2 and DDR3 use less than DDR1, the only thing that has been kicking things up were GPUs, and even there the worst was the 2900XT from ATi. Perhaps when having two of those you'll need more than 600W, though I know the system won't use much more than 400/500W for an average person. (that's probably where the efficiency plays parts).

Edit: Thanks for the info James Miller. I did quite a bit of review of PSUs, but that was about two or three years ago, so things have changed. I know that nowadays the best try to keep a >80% efficiency, and I'm glad to see that they are doing so at about every amount of wattage given

[Squall-Leonhart]

well the upside to having the headroom at 60-70% usage, is that you can add more harddrives or fans, or even custom light mods, without having to buy a new, probably $AU200+ PSU, so for me that would be a good reason to go all out with getting a psu, i only upgrade components when i need to, so knowing the PSU has the headroom to spare, is a load of my wallet ;P

Believe it or not, its actually the MCP and chipset that use the most power these days, after the video card that is, considering you have all those onboard items like Audio, USB, networking, Fan headers, etc, then you have HDD's CDR's, PCI Devices and then the CPU. so its not hard to see why Power requirements have indeed jumped. Gladly, its coming to the point where the next evolution of computing is approaching which may hopefully power requirements drop for mainboards, atleast i hope so.

As to heat, a good quality built PSU should not exceed 40c, My Toughpower 600, with its large industrial caps, and huge as hell heatsink (which is why they are so damn heavy) rarely passes 29c, even on a hot humid day. you can expect low quality systems to get hotter since the components aren't built accordingly... My old antec truepower 480 for instance would reach 37c, and upon ripping the thing apart (since warranty had expired, i salvaged the fans) i came to find a pissass tiny heatsink, and a bunch of leaking, almost exploding, capacitors.

Though again, the temperature is related to the power draw, the more power drawn, and used, the hotter the components would be. so again, even with a 700w psu, if your only using say, 400w, the temperature should still be low. And again, by buying quality components (which means anything not from codegen, TT and Antec, and probably many more) The chance of high temperatures decreases further still.

[Juppy]

Wow. That's alot of information. What do you guys think of Acbel 470W PSU? Is it a good quality PSU? Its the one I'm using now.

Another question since I don't wish to create another topic. :P

I'm currently using 2 sticks of Crucial DDR2 PC5300 637MHz 1GB RAM.
I wish to purchase two more sticks. Will it be alright to purchase 2 more sticks of DDR2 PC6400 800MHz 1GB RAM?
Also, will other brands do? My motherboard supports 800MHz by the way so it isn't a problem

Edit: I was browsing through Amazon.com for the prices of 8800GT and most of them were near $200. What currency is that in? US$? Anyway, that's not the main reason I edited the post. I saw a few 9600GTs there cheaper than the 8800GT. Why is that so? Is the 9600GT performance better?

Edit: I read a few benchmarks of the 9600GT and I realised the performance is lower than the 8800GT.

[Juppy]

bumpp. Anyway, Will 8800GT work on my motherboard since it requires a PCI Express 2.0 x16 slot.

Here is the specifications of my motherboard

[SCHUMI-4-EVA]

yes PCI Express 2.0 is backwards compatible with the original PCI Express

[Juppy]

Will the original PCI Express slot bottleneck the performance?

[Cheesus]

Nope...

[refraction]

as long as your slot is x16, you wont have any problems.

[Juppy]

Ok thanks. What about the RAM compataibilty issue?

I'm currently using 2 sticks of Crucial DDR2 PC5300 637MHz 1GB RAM.
I wish to purchase two more sticks. Will it be alright to purchase 2 more sticks of DDR2 PC6400 800MHz 1GB RAM?
Also, will other brands do? My motherboard supports 800MHz by the way so it isn't a problem

[Squall-Leonhart]

sure, but make sure you create a slipstreamed Vista install disk otherwise installation problems might occur when 4ghs is installed.

[Juppy]

Originally Posted by Squall-Leonhart

sure, but make sure you create a slipstreamed Vista install disk otherwise installation problems might occur when 4ghs is installed.

How do I create it? I have the original Vista disc. Slipstreamed means the CD key is already activated when you install right?

[refraction]

Originally Posted by Juppy

How do I create it? I have the original Vista disc. Slipstreamed means the CD key is already activated when you install right?

nope slipstreamed means any service packs the operating system has are already installed on the disc, so if you slipstream service pack 1, as soon as you install vista, you will be on service pack 1.

what you are referring to is known as an "unattended install"