I Need Help Understanding My Psu For A Gpu Upgrade

Hello,

I bought a 2nd hand lenovo thinkstation (super cheap 3.3ghz 6core, PDF of specs) and I want to stick a new video card in it because I want DirectX 11+ to run new games (currently has a FX4000).

The problem: I dont understand PSU's volts & amps enough to completely know the limit of my GPU upgrade. The current PSU has 2 6-pin's connectors available. (With a 2 extra 4 pin power conns)

Current PSU: Picture of Specs
+5v -- 30a
+3.3v -- 25a
+12v1 -- 18a
+12v2 -- 18a
+12v3 -- 18a
-12v -- 0.3a
+5vs -- 3a
625watt total

Current PC Specs:
3.3 ghz 6 core
24gig EC ram
128gig ssd
Nvidia quaddro FX4000

Im looking to upgrade my GPU to potentially a GTX 970/960


Side question... I googled around at adapters, is it safe to buy an adapater to make an 8 pin PCI Express power cable? I'm just looking at my options here or do I have to stick with the 2 6'pins... limiting my GPU upgrade potential .

Thank you very much fellow hardware friends

 

The majority of 970's require 2x 6-pin (a few, like mine, an ASUS blower, require 1x8-pin), 960's use a single 6-pin. Wattage is in the 140-200 range for the 970, 120-150 for the 960, depending on clock rates and how much it's overclocked.

I'd guess at your PSU requirements being a ~500w model, check using this PSU calculator.

Depending on how hard your rig has been used, the current PSU looks like it should be fine but they do degrade over time.

Using adapters does carry some risk, avoid where you can.

 

According to the image of your PSU specs, it is a 625W, 80 PLUS "Bronze" supply. And according to various GTX 970 cards I looked at, the specs recommend a "minimum" 400 to 500W PSUs. So in theory, your supply (if working properly) should be fine.

My only concern is two-fold. While Lenovo does make some reliable computers, they don't have a stellar reputation for honesty - though that is mostly do to security and the protection of their user's privacy. Still I don't trust Lenovo, the company. And to that, we cannot see the brand of that power supply and there have been cases where counterfeit supplies with trumped-up specs and fake 80 PLUS logos have been used.

If not legitimate, I doubt the supply would hurt your new card. But if you start having stability issues (sudden reboots, shutdowns, or system freezes) after installing the card, I would shop around for decent 600 - 650W 80 PLUS, at least Bronze preferably Gold supply from a reputable maker. I recently have been using EVGA Gold supplies in our builds here and really like them.

I agree completely with satrow about adapters. They are okay to power case fans and drives, but for critical systems like the motherboards and graphics cards, it best to get a supply with the correct connectors.