What wattage of PSU do I need?

[wigglerthefish]

Hello,
I'm torn between 2 different PSUs. They are the same (?) except for the wattage (650 and 750). After, my build won't be upgraded other than an additional 6870 (at a later time). Do I need a 750 W PSU for this crossfire if im not going to upgrade for a while? Is a 650 W PSU suffice?

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006

I am trying to cut corners as much as I can to keep it under $1000...

My (soon-to-be) build:
ASUS M4A89TD PRO/USB3 - MOBO
HIS H687F1G2M Radeon HD 6870 (x2 at a later date) - GPU
AMD Phenom II X6 1055T Thuban 2.8GHz - CPU
G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 - RAM
Western Digital Caviar Black WD6402AAEX 640GB 7200 RPM SATA 6.0Gb/s 3.5" Internal Hard Drive - OS and Storage
ASUS DRW-24B1ST/BLK/B/AS Black SATA 24X - DVD Burner

Also, I am going to buy an aftermarket cooler and OC the CPU a bit.

 

[dogman_1234]

Hello, and welcome to THG.

I would personally get an 800 watt...just fo more space and if you want to upgrade later. The extra wattage would give you breathing room for OC as well.

 

[wigglerthefish]

Well, I don't think I need that much... Aren't the 6xxx series more power efficient? Besides, the tech will be outdated won't it? Will 750W be enough to OC the CPU and GPU(s)?

 

[beanoslim]

You'd be fine with a decent 650w running XFire.

If the card needs 2x6pin or 1x6pin and 1x8pin you will need a psu that has 4x pci-e connections for Xfire.

I'd go for one of these, they are in order of preferance, all are very capable.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151088
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139012
http://www.newegg.com/Product/Product.aspx?Item=N82E16817207002

Just noticed the 750w you listed was $99 after rebate and has 4xpci-e, might as well get that.

 

[wigglerthefish]

Thanks. I checked it though, I won't have the resources to buy all of the components by then so the cost will be $110 for me... Its not modular though and I may have a better 1st time experience with modular.

 

[beanoslim]

The Seasonic is the best choice if you can stretch to it and modular.
Otherwise the XFX will do the job nicely and is modular for $99.
Or the Corsair 650w is in the middle, modular and has a 7 yr warranty!

 

[wigglerthefish]

Sounds good! If the price stays the same I'll probably get the XFX one. It does have some nasty reviews though.

 

[beanoslim]

More good than bad, its always like that, it gets good reviews from psu reviewers, thats more important.
$69.99 with rebate, snap it up-
http://www.newegg.com/Product/Product.aspx?Item=N82E16817207007

 

[wigglerthefish]

Do you think its worth cutting out of the other components to get a 6950 instead (2GB VRAM)?

 

[wigglerthefish]

AND MODULAR!!! WHOOO! Do you think it'll stay in stock? (I might have to buy it now...)

 

[wigglerthefish]

What is a 6+2 pin? (6+2=8)

 

[beanoslim]

What do you mean cutting out? Getting 1 6950 instead of 2 6870's?

Its the same as the 1st XFX but with a grey fan that I like anyway.

Some cards need an 8 pin pci-e cable but they manufacture them as a 6pin + the 2 extras if needed.
If they made them 8 pin and your card needed 2x6 pin you'd be stuck.

 

[wigglerthefish]

Oh. Well I can't afford 2x 6870 right now, but I'm thinking about sacrificing on other components (like CPU) to get 1x 6950 and maybe get another later...

 

[wigglerthefish]

Will 620W be enough? And its not modular... Thanks though

 

[wigglerthefish]

Mmm are you going to flash the 6950 bios by any chance?

Yes, but I won't OC it to 6970 Specs, just unlock the additional stream processors.

 

[beanoslim]

Do you need 6 cores or a x4 965?
This might interest you - http://www.tomshardware.com/forum/305162-33-6870-6950

 

[wigglerthefish]

Do you need 6 cores or a x4 965?
This might interest you - http://www.tomshardware.com/forum/305162-33-6870-6950

Well you see... The one thing I do NOT want to sacrifice on in a game is the view distance. I think 2 GB should boost that higher than a 1GB...

 

[wigglerthefish]

http://www.techpowerup.com/articles/overclocking/vidcard/159

Have a look at this if your looking at the 6950

Yes, that is the reason I am looking at the 6950 now (before I was looking at the 6970).

 

[wigglerthefish]

The 945Be version are 20usd cheaper. Its the same chip. you pay 20usd per 200mhz. So 955 are 20usd more 3.2ghz and the 965 another 20usd more at 3.4Ghz. So if your overclocking you might aswell get the 945BE version and save 40usd by overclocking it to 3.4 yourself

Yeah but I would have to spend the $70 to buy the beast of an aftermarket cooler I want. Besides, can you reach 4GHZ with the 945Be just as stable?

 

[beanoslim]

Will 620W be enough? And its not modular... Thanks though

Probably not for XFire and it only has 2xpci-e, should be ok if you decide on the 1x6950, and like you say non modular.

The XFX is cheaper with rebate anyway.

 

[wigglerthefish]

Probably not for XFire and it only has 2xpci-e, should be ok if you decide on the 1x6950, and like you say non modular.

The XFX is cheaper with rebate anyway.

I just saw that too...

 

[wigglerthefish]

Dont know what's that mobo of yours is priced but you can have a look at this one.

http://www.newegg.com/Product/Product.aspx?Item=N82E16813157198

Then look at this hdd

http://www.amazon.com/gp/aw/d.html/ref=redir_mdp_mobile/187-4913597-6733051?redirect=true&tag=hardwarevol03-20&linkCode=as2&a=B001U3S5S0&camp=1789&creative=390957&creativeASIN=B001U3S5S0

Well, its expensive because it has 2 PCIe 2.0 x16 slots BOTH @ x16. I want to get the most out of my xfire in the future.

 

[wigglerthefish]

No 25usd actually.

Well I've taken a liking to the Zalman CNPS 9900MAX...

 

[wigglerthefish]

Dont know what's that mobo of yours is priced but you can have a look at this one.

http://www.newegg.com/Product/Product.aspx?Item=N82E16813157198

Then look at this hdd

http://www.amazon.com/gp/aw/d.html/ref=redir_mdp_mobile/187-4913597-6733051?redirect=true&tag=hardwarevol03-20&linkCode=as2&a=B001U3S5S0&camp=1789&creative=390957&creativeASIN=B001U3S5S0

On the HDD, will Sata 3GB/s impact performance? Also, the 640GB model I picked out had a 64MB Cache, not 32MB. Storage isn't important to me (no music or video or pictures.).

 

[beanoslim]

Well I've taken a liking to the Zalman CNPS 9900MAX...

I've just got myself the Venomous X Black, I've had Zalman 9500 and 9700 but they can't live with the towers now.