PSU requirement (Altered requirements)

[Miganto]

Hi, i am about to buy a new pc, and i have a general idea as to what i am going to get, but have no idea about the current generation of power supplies, and was wondering if i could get some advice.

I will be getting;

c2d e8500
4870 1GB, or a 4850x2 2GB (I heard that it needs certain pins?)
~320GB HDD
Samsung SM2333W (23inch monitor)

I think that's all that draws any major power?

I was thinking i'd need a ~500w psu?

Thanks for any advice you can give =)

Editted to remove the 2nd gpu requirement.

 

[starfireone]

A 750w will workl nicely for your system and give you enough watts to add other components later without having to upgrade the PW.

 

[Miganto]

OK thankyou. May i ask, if i have a 700 watt, but use only say...400 watts of it at the moment, is the other 300 watts still drawn from the power supply and wasted?

I've decided to just use a single gpu board, and upgrade the gpu in a few years when it's needed, rather than run crossfire. With that in mind, would i need something closer to 500w? (Would i be able to get away with a 450w?)

Would i need a certain style of PSU (crossfire/sli) for a 4850x2? (Single card, 2 gpus)

Any suggestions on a good sturdy power supply that'd be suitable?

 

[HOOfan 1]

Originally posted by: Miganto
OK thankyou. May i ask, if i have a 700 watt, but use only say...400 watts of it at the moment, is the other 300 watts still drawn from the power supply and wasted?

No...the PSU only outputs what it needs to output...otherwise the rest would be wasted as heat...and added heat is not good. What your computer draws from the wall depends on efficiency.

If you have a 700W PSU and your computer needs 350W of DC power, the PSU will output 350W of DC power, if the PSU is 82% efficient at 50% power draw then it will pull 427W of AC from the wall...note there is no such thing as 100% efficiency.

I've decided to just use a single gpu board, and upgrade the gpu in a few years when it's needed, rather than run crossfire. With that in mind, would i need something closer to 500w? (Would i be able to get away with a 450w?)

That depends on exactly what card you plan to buy.

Would i need a certain style of PSU (crossfire/sli) for a 4850x2? (Single card, 2 gpus)

Any suggestions on a good sturdy power supply that'd be suitable?

Style (i.e. Sli or crossfire certification) is not important those are only obtained by paying ATI or nVidia to test them and allow bullet points for marketing on a box. However, certification pretty much means that the power supply is capable of doing what it is certified for. Quality, 12V current available and wattage rating are important.

for a 4870X2...600W plus is a good idea.
Corsair TX650, HX620, TX750
BFG LS680
PC P&C Silencer 610 or 750
Coolermaster Real Power Pro 750W
Pretty much any Silverstone Model above 600W
Enermax Liberty Eco or Modu82+ or Pro82+ 600W+

 

[Miganto]

Very very nice reply there Hoof! Thankyou for clearing up so many things.

I've nearly finalised my system, it'll be something like this;

c2d e8500
4GB ram
UD3R board
LG 22x dvd
320GB WD blue

With either a 4870 1gb, or a 4850x2 2GB (I can only buy from Israel and prices are a lot different here than in England/US, so it's not as easy to chose between them ;D)

From the anandtech test http://www.anandtech.com/video/showdoc.aspx?i=3517&p=13 I see that the load was only at 287w(4870) or 330w(4850x2). I realise i should get a fair amount more, as it's not at full load, but wouldn't 600 be overkill? (600's cost quite a bit more than 500w's in israel, hence the lower the wattage the better really)

Would the i7 be drawing more power than the e8500 as well?

 

[HOOfan 1]

Oh I thought you were saying 4870X2.

Well for a 4850X2 500-550W would be fine. Typical thinking is that it is best not to run your PSU beyond ~65%-70% of its rated output for an extensive amount of time.

 

[Miganto]

That's good news then =)

I was thinking that this http://www.newegg.com/Product/...x?Item=N82E16817139004 or this http://www.newegg.com/Product/...x?Item=N82E16817139003 are a good type of PSU for my requirements. I might possibly OC my processor a tiny amount in the future, but nothing major. Up to 3.8GHZ, tops. I think 450 might be cutting it too fine, so possibly i should go with the 550? Does it seem like a good (read mid-to-mid-high end) PSU?

Thankyou for all your help by the way.

 

[HOOfan 1]

for a 4850X2 and OCing, I would certainly go with 550W and yes the Corsair VX550 is one of the best 500-600W PSUs available.

 

[cusideabelincoln]

Go with the 550W Corsair. While you could use the 450W, I wouldn't recommend it, especially since you have plans to use this power supply in future builds. Also the 450W only has one PEG connector, and the HD4850X2 needs two. While you could use an adapter to get the extra PEG connector, just go with the 550W Corsair since it comes with two anyway.

 

[Miganto]

Ah great, so if i wanted the x2, i'd need to get the 550 for the connection, good info, thankyou.

If i were to only use a 4870 single, would a 450 be ok? Only asking, as the x2 looks like it might be £120+ / $200+ more expensive than the 4870 here

 

[theAnimal]

The 4870 also requires 2 PCIe connectors.

 

[Miganto]

Excellent, question answered then. Thanks to all that helped!