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4870 on a corsair vx450

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August 16, 2008 2:49:59 PM

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


will it work?

More about : 4870 corsair vx450

August 16, 2008 3:01:23 PM

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.
August 16, 2008 3:41:23 PM

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 :D 
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August 16, 2008 4:09:46 PM

Yeah worse case you'll get bsods, artifacting, random lockups and restarts but your not going to fry any components.
August 16, 2008 4:55:45 PM

I wouldnt run a 4850 on that PSU, spend some dough and get a 650-750 watt.
August 16, 2008 5:13:23 PM

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=MTUzMSw5...
August 16, 2008 5:31:53 PM

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.
August 16, 2008 5:41:09 PM

PsyKhiqZero said:
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.
August 16, 2008 5:52:08 PM

@ 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.
August 16, 2008 5:53:59 PM

PsyKhiqZero said:
@ 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. :na: 
August 16, 2008 5:57:05 PM

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
August 16, 2008 6:11:15 PM

JAYDEEJOHN said:
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.
August 16, 2008 6:14:43 PM

I'm just too dam slow
August 16, 2008 6:25:36 PM

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.
August 16, 2008 6:27:24 PM

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.
August 16, 2008 6:31:13 PM

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
August 16, 2008 6:35:12 PM

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
August 16, 2008 6:47:02 PM

PsyKhiqZero said:
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
August 16, 2008 6:55:13 PM

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.
August 16, 2008 7:07:52 PM

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
August 16, 2008 7:11:15 PM

PsyKhiqZero said:
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.
August 16, 2008 7:12:58 PM

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 :D 
August 16, 2008 7:25:49 PM

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.
August 17, 2008 12:27:13 AM

dagger said:
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
August 17, 2008 12:31:11 AM

JAYDEEJOHN said:
Look, go to jonnyguru, see how he tests. He looks for psus to achieve best at 80% usage.

Jonnyguru looks for at least 80% efficiency... but always tests full rated wattage.

-mcg
August 17, 2008 12:38:10 AM

Of course he does, but its a fail if at 80% theres a tail off
August 17, 2008 4:54:54 AM

MrCommunistGen said:
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



crap, i dont wanna be a guinea pig here lol. i dont wanna change psu's because it'll be hell to pullout the psu then connect all the cables from the new one. graaaahh just the thought of it made me wanna bang my head on the wall. and buying a new psu is also not a financial option, as crysiswarhead and spore is just around the corner, ive specifically allocated my remaining funds for this 2 games right here. it will suck to have a new gpu but with no new games to play with am i right?

but can you somehow explain to me the readings from the anandtech stats? the 4870 reads @ 278w. what does that mean?
August 17, 2008 6:04:42 AM

Why dont buy the **** HD4850, you moron??
August 17, 2008 6:25:27 AM

JAYDEEJOHN said:
Of course he does, but its a fail if at 80% theres a tail off

Ahh... now I understand what you were trying to say the first time around.

-mcg
August 17, 2008 8:00:30 AM

Alatriste said:
Why dont buy the **** HD4850, you moron??


because i have the money for a 4870 right now you fcktard.
August 17, 2008 8:33:25 AM

fcking bastard your pc will burn in hell

pd: ihave thesame psu

STUPID IDIOT DONT HAVE THE CONECTORS FOR PCI-E
August 17, 2008 4:11:20 PM

Alatriste said:
fcking bastard your pc will burn in hell

pd: ihave thesame psu

STUPID IDIOT DONT HAVE THE CONECTORS FOR PCI-E

You can still use sata to pcie or molex to pcie connectors. That's no problem. But I agree in that it'll still burn. :p 
August 19, 2008 6:41:29 PM

Based strictly on the numbers your VX-450 will run this card. But, you may be running the PSU at a very high percentage of its rated output which is not good for long term usage. An HX-520, VX550, or TX650 are much better choices if you get the 4870.

Corsair PSU Finder: http://www.corsairmemory.com/psufinder/default.aspx
!