4870 on 460W can it happen???

[Flyordie]

While we're on the subject of cars... here's another analogy for those who swear that because their name-brand PSUs are rated for 380w and since their system draws 340w they're okay.

If you have a car, wouldn't it almost certainly last longer with fewer problems driving it normally (i.e. if the engine's redline was at 6.5k rpm, going up to no more than 4k rpm) than driving it near redline for the life of the car? Same thing with PSUs... yes, you CAN run it at or near the maximum rated wattage but that's a risk that you're taking. Having a comfortable buffer zone would almost certainly help towards extending the expected lifetime of the PSU.

That said, I'm with the others on getting a quality brand PSU that is rated for at least 550w (preferably higher). Provided that you get a high-wattage PSU now, you can carry that PSU over to your next build and the one after that and the one after that, etc.

Well considering that no other company besides Seasonic rates their PSUs at 65C.. I would say I am really running a 450-480W PSU since its running under 35C at all times. Its also not like I am using a single rail PSU. The HD4850 has its own dedicated 12V Rail since the HDD/Opticals don't use the 12V Rail. The EA380 is rated to sustain 380W @ 65C 24/7. So I would think it could sustain 300-320W 24/7 @ 35C. Depends on the conditions the PSU is set into if it fails before the warranty is up (lucky me, lifetime warranty on my EA380). Mine is a well planned, balanced machine. I bought it because at the time I was never planning on running Xfire, it supplied me with the wattage I needed and at an 85% efficiency rating.
You heard my recommendations in a prev post, so stop badgering me for using a VERY HIGH QUALITY 380W PSU (that is very well capable of outputting 410W 24/7.) This PSU also, under full load only chucks out "luke warm" air... not even over 75F. So... heh.

Fly

 

[mrhuggles]

watts dont matter, go for something with around 60a or so on the 12v rail

EDIT: i love my psu, its usualy around 140 bux on newegg and its really a remarked seasonic with a big single 12v rail]

 

[Flyordie]

watts dont matter, go for something with around 60a or so on the 12v rail

Mine...
+3.3V@20A,+5V@20A,+12V1@17A,+12V2@17A,-12V@0.8A, +5VSB@2.5A
130W Max on the +3.3 and +5.0V rails
330W Max on the +12V Rails

 

[mrhuggles]

2x 17a 12v rails is not enough.

sorry, i mean you can do it but its gonna kill that psu for sure after a while.

 

[trickson]

Well my car needs an oil change. I don't have any 10W-30, but I do have some Crisco... I should just TRY to use that, right?

While we're on the subject of cars... here's another analogy for those who swear that because their name-brand PSUs are rated for 380w and since their system draws 340w they're okay.

If you have a car, wouldn't it almost certainly last longer with fewer problems driving it normally (i.e. if the engine's redline was at 6.5k rpm, going up to no more than 4k rpm) than driving it near redline for the life of the car? Same thing with PSUs... yes, you CAN run it at or near the maximum rated wattage but that's a risk that you're taking. Having a comfortable buffer zone would almost certainly help towards extending the expected lifetime of the PSU.

That said, I'm with the others on getting a quality brand PSU that is rated for at least 550w (preferably higher). Provided that you get a high-wattage PSU now, you can carry that PSU over to your next build and the one after that and the one after that, etc.

 

[mrhuggles]

anyways, i like my psu, if you wanna find something cheaper it shouldnt be hard just pay close attention to how big the 12v rail is, personaly i prefer large single 12v rails but i dont see why having like 4 or 5 18a rails wouldnt be good enough.

 

[Flyordie]

2x 17a 12v rails is not enough.

sorry, i mean you can do it but its gonna kill that psu for sure after a while.

Well...
HD4850 only draws 110W (125W OC'd). Thats on rail 12V2. (17A x 12V= 204W Max load for that rail... so 52% load.)
CPU draws 100W so again... 100W. The 12V1 Rail is at 49% load.
So how again am I stressing it?

 

[anticlutch]

lol hitting your head against a brick wall won't help much

Everyone has their own opinion, be it that maxing out your PSU's rated wattage is fine or that you should have a buffer zone. I personally think (and am more comfortable with) having more wattage is better as higher wattage generally means that it can handle more (amps on rails included). For those who decide to get the lower wattage PSUs, I wish you the best of luck as you are far braver than I in terms of risking computer components. I know that I won't be able to change your mind and you probably won't be able to change my mind so the best way to handle things is to agree to disagree.

 

[erocker]

I'm quite sure this thread has gone far enough. We all now know that a quality PSU with more wattage is, of course a better PSU. ATi clearly states the recommeded wattage and amperage that is required to run the card. Follow their instructions. You have all made your points over and over again, this thread is nothing but a broken record. If you have some kind of super-duper groundbreaking inforation on this subject, please fell free to post. However, if you just want to regurgitate the same thing that you've said previously.. Please we have all heard enough. Thanks.

 

[mrhuggles]

oh sorry, was thinking you were the guy wondering about if a 4870 would work :? i got confused.

EDIT: also, i have read that 4870 uses more than 2900xt [actually i dont know exactly how much the 4870 uses.]

 

[Flyordie]

lol hitting your head against a brick wall won't help much

Everyone has their own opinion, be it that maxing out your PSU's rated wattage is fine or that you should have a buffer zone. I personally think (and am more comfortable with) having more wattage is better as higher wattage generally means that it can handle more (amps on rails included). For those who decide to get the lower wattage PSUs, I wish you the best of luck as you are far braver than I in terms of risking computer components. I know that I won't be able to change your mind and you probably won't be able to change my mind so the best way to handle things is to agree to disagree.

I am set firm on the 75-80% load range. Its where PSUs are most efficient and love to run. They fail the most at under 35% load at the low end of the spectrum and fail at 90-120% of the high end spectrum. That is for the PSUs that are built right, like the Earthwatts series. So I have no fear. If it brings a PC with it, Antec will replace it. They have done it before. Its in the warranty contract I signed with Antec when I bought the PSU. ;-) Its also why OVP exists.

Fly
*just read' erocka's post* and hug's...*
HD4870 draws 130W Maximum.

 

[mrhuggles]

gee thanks, wow i guess all i read about the 4870 soaking up tons of power was wrong :?

 

[eidairaman1]

I'm quite sure this thread has gone far enough. We all now know that a quality PSU with more wattage is, of course a better PSU. ATi clearly states the recommeded wattage and amperage that is required to run the card. Follow their instructions. You have all made your points over and over again, this thread is nothing but a broken record. If you have some kind of super-duper groundbreaking inforation on this subject, please fell free to post. However, if you just want to regurgitate the same thing that you've said previously.. Please we have all heard enough. Thanks.

THx for Stepping in.

 

[cdawall]

I don't BSOD... Im 100% stable... even got my X2 overclocked. Let me show you something...

As you can clearly see, the reviews are GREAT.... My voltages aren't sagging like an old woman's (.)(.)... So, until you can come up with another reason... enough of your crap.

your 12v rail is running from 11.84 to 12.16v your 3.33v isnt even @3.33v peak, and your 5v is anywhere from 4.95v to 5.03v thats ummm pretty shitty



get a better PSU end of argument even dell specs higher PSU's then that on there videocardless quad core systems


PCP&C SLi turbocool 510w

been running for 30min look at the rails and i know the 3.3v is running a little low i haven't had a chance to tweak it to 3.3v yet



here is the step down from my PSU it should run your rig no issues

http://www.newegg.com/Product/Product.aspx?Item=N82E16817703015


or you could get this for a little more and not worry about PSU's fro several years

http://www.newegg.com/Product/Product.aspx?Item=N82E16817703005

 

[Wile E]

No, it isn't shitty, cdawall. First, all of his readings are still better than ATX specs for regulation, and second, voltage reading progs aren't exactly the most accurate when it come to rail voltages.

 

[Flyordie]

that reading was over a 38 hr period. ;-)
I will be upping to an 850W PSU in March, in preperation for my migration to an AM3 Crossfire Setup. ;-)
This one to be exact...
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371009

edit-
cda
When they spec their PSUs they are built by a 3rd party OEM that most people probably have never heard of. When I say Seasonic, does that name ring a bell for being a great PSU manufacturer? Yes. So of course they will give a quad core system a 500W PSU... they are putting it at 30-40% load that way.

 

[eidairaman1]

Good PSU dude.

 

[SiliconSlick]

Probably too late but more hype IMO

Hey might be buying a new 4870 for christmas. Problem is I might not be able to get a new power supply... So I dare to ask the question... Can a 4870 run on a 460W switching power supply?

Spec

ATI HIS HD 4870 512MB GDDR5 PCIe

Thermaltakes power calculator puts you at 301 watts on your current rig...

So YES, that PS would do it.

http://www.thermaltake.outervision.com/Power

You probably already dove ahead.
________________________________

There's a LOT of hype with power supplies, because people ALWAYS report their blowouts, and people are extra cautious quite understandably for their new parts, and it's always nice to brag that you "need" a 1000 watt monster.

Shall I grab the TH link where SLI and QUAD is run on a good 430 thermaltake ?

Oh well, too late, and it is safer with newer power protection in the latest supplies.

 

[silkstone]

Now this is great advice ! Take TO!
I myself would not try putting a 4850 or any thing like it on a PSU with less than 500W Max ! I would IMHO get a PSU that can put out at the very least is 700W and a name brand some thing people trust . I like Enermax but I have a rocketfish that is really proving to be a very stable and reliable PSU .

I ran my 4850 on a no name chinese! psu for a while with no problems. But after reading advice on different threads i decided to upgrade to a decent brand (little known - but good quality) It's 470w and runs a 4850 fine. Personally i think buting a high watt psu is over-rated, but buying a decent psu is a must. I, myself, won't upgrade the psu when i add another 4850 unless i run into stability issues.

 

[trickson]

The problem is when stability becomes an issue it maybe to later as it could take some parts with it as well .

 

[silkstone]

With a high quality PSU it shouldn't cause an issue, it'd just not provide enough power to certian parts.

The first sign of not enough power would come when you write cd's or dvd's (it did for me on an old laptop).
A good test would be to write a dvd while benchmarking thus giving you 100% max power use.