4870 on a corsair vx450

[wh3resmycar]

q6600 @ 3.0ghz
p5k-se
1 640gb wd
1 dvdromdrive


will it work?

 

[PsyKhiqZero]

It prolly will work. I'm not a 100% sure but it seems the power requirements for GPU are always way over estimated. Take a look at the total system power draw for the 4870 according to anadtech.

http://www.anandtech.com/video/showdoc.aspx?i=3372&p=10

Worse case you can always step up the power supply if it doesn't work.

 

[wh3resmycar]

cool, seems like a 4870 "might" work. for starters the only stability problem i may encounter is a bsod right? or am i talking fried psu/gpu here?

what was the setup anand's was using? was that on oc'd qx?

i'll get one nextweek

 

[PsyKhiqZero]

Yeah worse case you'll get bsods, artifacting, random lockups and restarts but your not going to fry any components.

 

[kawininjazx]

I wouldnt run a 4850 on that PSU, spend some dough and get a 650-750 watt.

 

[dirtmountain]

You'll only be at about 320-350w at load, a Corsair 450w should be fine with the system you listed
http://extreme.outervision.com/PSUEngine

 

[dagger]

An oced 65nm quad consumes a lot of power on full load, there is more to a computer than just a gpu. Then keep in mind only a part of total wattage goes to 12v rail(s), which powers cpu, gpu, hdd... basically all the major power consumers. The portion that goes to 3v/5v rails are more or less wasted. There is also 12v ampage, if too low, it'll further limit output. Also note that even the best psu's output fluctuate on near full load, destablizing the system. Manufacturers usually recommend 60% or below max load. What they advertise isn't what you get. In other words, your current psu won't cut it.

Power consumption:
http://enthusiast.hardocp.com/article.html?art=MTUzMSw5LCxoZW50aHVzaWFzdA==

 

[PsyKhiqZero]

80 percent of 450 watts is about 360 watts (the unit is 80% certified). Under full load hardocp measures 359 watts. Keep in mind their refernce system includes an Intel extreme quad, 3 raptors and a watercooling rig.

I totally agree that if you have the money, go buy a 750watt unit along with the 4870. but you'll have to admit that given real world numbers compared to the overstated system requirements...it's worth a shot.

 

[dagger]

80 percent of 450 watts is about 360 watts (the unit is 80% certified). Under full load hardocp measures 359 watts. Keep in mind their refernce system includes an Intel extreme quad, 3 raptors and a watercooling rig.

I totally agree that if you have the money, go buy a 750watt unit along with the 4870. but you'll have to admit that given real world numbers compared to the overstated system requirements...it's worth a shot.

The problem is, again, not all power goes to 12v rails, yet basically everything draws from 12v rails. Benchmarkers use very large psus for tests, so they're not limited in that way.

 

[PsyKhiqZero]

@ dagger assumming your right and the 450 watt unit will not work, what do you gather the worse case senario will be?

Cuz i'm thinking about 2 hours of wasted setup time and 3-5 business days waiting for a new PSU.

 

[dagger]

@ dagger assumming your right and the 450 watt unit will not work, what do you gather the worse case senario will be?

Cuz i'm thinking about 2 hours of wasted setup time and 3-5 business days waiting for a new PSU.

Lol, good point. +1.

 

[JAYDEEJOHN]

Still, a small portion of the overall is 5 and 3.3 volts. I wouldnt try it. If it were a 4850, then yes, but a 4870 draws 45 more watts than the 4850, and being that a 4850 is close, a 4870 to me is over the top

 

[dagger]

Still, a small portion of the overall is 5 and 3.3 volts. I wouldnt try it. If it were a 4850, then yes, but a 4870 draws 45 more watts than the 4850, and being that a 4850 is close, a 4870 to me is over the top

A quick google search:
http://www.silentpcreview.com/article751-page1.html

396 out of 450 watts is 88% going to 12v rail, which is quite good. It's typically around 80% for the average psu. While small, it's still significant.

 

[delluser1]

I'm just too dam slow

 

[PsyKhiqZero]

AT this point I couldn't careless about being right or wrong. I just wanna know if it works. hopefully the OP will give us an update when their 4870 arrives.

 

[dirtmountain]

But that HardOCP was using a QX9770, 3 Raptor hard drives,floppy and a Koolance Exos water cooling and still only hit 359w at load or about 72% of the Corsairs listed power. Agreed if he was buying a new PSU for that system it's not what i'd recommend, but imo it should be fine.

 

[JAYDEEJOHN]

If the psu is new, and if its reliable and if its made well even if from a good manufacturer, itll work....for awhile. Eventually itll burn up. And when the psu goes, who knows what could happen. If its being drawn to its highest output, itll get hot. Heat causes electrons friction, meaning they bounce around more, are more erratic, causing friction, which causes more heat, thus more demand for power. Viscious cycle, eventually itll go. And who knows what itll take with it

 

[JAYDEEJOHN]

80% is the recommended high output from a psu. Hes on the edge with this. Somewhere I personally wouldnt go. Look, go to jonnyguru, see how he tests. He looks for psus to achieve best at 80% usage. Now remember, this isnt peak, its constant under gaming loads

 

[MrCommunistGen]

80 percent of 450 watts is about 360 watts (the unit is 80% certified).

Oh my... that's not at all what 80% certified means. It doesn't mean that the unit puts out 80% of it's rated power, it means that the unit is at least 80% efficient in converting AC power to DC power. Meaning a 450W PSU with 80% efficiency will put out 450W, but in doing so will draw 562W (450W/0.8).

That said, from what I get using the extreme outervision PSU calc, the Corsair VX450 would not be a good long term solution for powering an overclocked quad and an HD4870.

-mcg

 

[PsyKhiqZero]

Thanks MrcommunistGen for correcting me. But isn't that more of a reason why the vx450 will work? Even with hardocp uber reference rig, the total draw is 360watts. And since hardocp did their measurements at the wall that means the 360 watts they measured is only like 288 watts at the psu which leaves 162 watts to spare.

 

[JAYDEEJOHN]

Like I said, that isnt peak power usage, only constant draw under gaming. It will go higher than that. At 80% usage is where you seperate a good psu from a bad one, or so jonnyguru would have us believe. Thats where its being tested, worked the hardest, where its supposed to handle its utmost challenge. Doing that on a day to day basis to me is asking too much

 

[dagger]

Thanks MrcommunistGen for correcting me. But isn't that more of a reason why the vx450 will work? Even with hardocp uber reference rig, the total draw is 360watts, that leaves 90 watts to spare.

Again, for that particular psu, 12% cannot be used, resulting in 396 out of 450 watts. Plus the hardocp test is done while running gpu stressing utility that does not stress cpu. Basically, yes, it's a qx9770, but it's idling. As time go on and programs get more taxing, you may not be able to idle your cpu like they do. Due to inefficiencies as voltage and clock rate increase, an oced q6600 at 3.6ghz at full load can consume upward of 220w alone, depending on vcore. 3.0ghz will consume less, but probably still a lot. Not to mention qx9770 is based on more efficient 45nm process, compared to q6600's 65nm process, at the same clock rate, your q6600 will hog significantly more power.

 

[homerdog]

If you're buying a new PSU it would be wise to get something a little more powerful, but if you already have a VX450 it should power a single HD4870 just fine. You will need a molex -> PEG adapter though as the VX450 only has one 6pin PEG connector.

And thanks MrCommunistGen for correcting PsyKhiqZero. I choked on my saliva a little bit when I read that post

 

[JAYDEEJOHN]

The way I see it is like buying an air conditioner. Itlls supply the amount of cooling for the square footage of your house say at 2 tons, but getting a 2.5 ton is more economical, practical, and if the 2 ton goes, its only takes it with it, nothing else.

 

[MrCommunistGen]

Again, for that particular psu, 12% cannot be used, resulting in 396 out of 450 watts.

Where did you get this? Sure systems use mostly 12v these days, but the 3.3v and 5v rails are being used too... they're not being "wasted". 33A on the 12V rail is quite a bit. Using the PSU calc here: http://www.extreme.outervision.com/psucalculatorlite.jsp I got 355W actual system draw with 3.0GHz , RAM, 1 HDD, an optical, and some fans... If you factor in capacitor aging at 15% you get 408W which is within safe limits. Just to throw it out there, the PSU calc estimates 121W for 3.0GHz @ 1.26v under full load.
Sorry for any confusion with my previous post about not thinking the PSU would cut it. I was going off specs other people listed and not what the OP said... and came up with a higher number (I used 3.2GHz and assumed 3 hard drives). The PSU should do fine.

-mcg