[SS SST-ST85F] Converting dual 6 pin PCIe connectors to a single 8pin

orestesp · 25 Aug 2017 at 20:12

I am re purposing an old Silverstone SST-ST85F Fully Modular 850W PSU.
However, it lacks PCIe 8pin power connectors, so I had to buy a cable from ebay that converts the dual 6 pin PCIe connectors on the power supply to a single 8pin connector, in order to power my RX 480 (pic related):

http://imgur.com/a/5gMBS
(The cable converts 2x6pin PCIe male connectors to a single 8pin female connector, which will then, through a male-to-male PCIe 8pin cable, will power the GPU).

Is this going to work or is it going to fry my graphics card?

Borealis · 25 Aug 2017 at 21:27

How old is this PSU? Twin 6-pin to one 8-pin adaptors do work but I wouldn't risk an old PSU with a new card. Any decent 850W PSU should come with 8-pin cables, unless it's so old it dates back to before 8-pin PCI-E cables existed.

orestesp · 25 Aug 2017 at 21:57

Borealis said:
How old is this PSU? Twin 6-pin to one 8-pin adaptors do work but I wouldn't risk an old PSU with a new card. Any decent 850W PSU should come with 8-pin cables, unless it's so old it dates back to before 8-pin PCI-E cables existed.

Here's a page that lists its specs:
http://www.sundialmicro.com/silverstone_modular_power_supply_sstst85f_1944_968.html

Support dual PCI-E 8 pin connectors & quad PCI-E 6 pin connectors

I shouldn't have any problems with it, right?

I salvaged it from a C2Q system that came with it.

Is there anything I need to look out for with the cable I am using?

Borealis · 25 Aug 2017 at 22:12

The connection is fairly straightforward, but that PSU is probably around 6-10 years old.

Having looked at reviews, it uses some lower-tier parts in places and over the course of 6+ years it will have degraded. What is this trying to power? If it's anything other than a basic/legacy PC, I'd get a decent modern PSU.

orestesp · 25 Aug 2017 at 22:18

6600k
RX480
2x1TB WD Enterprise Class HDDs, 128GB NVMe SSD

I currently have a VS 550, could it be worse than this?
The system it was used for didn't even have a discrete graphics card that required additional power.

Borealis said:
The connection is fairly straightforward

It won't fry anything, right?

Where did you find those reviews?

Borealis · 25 Aug 2017 at 23:05

It won't fry anything. Using 2 6-pin to single 8-pin has been around for a long time. Some cards still come with the adaptor.

Hard to say what's worse, the Silverstone or the VS550. The VS series are cheap units using some budget parts. They're the cheapest Corsair PSUs available. Personally I would use neither, as the PSU is arguably the most important component in the system but if I had to choose, I'd go with the VS. as it's newer.

If this is the correct model, here's a review. Page 4 is disassembly showing the internals:
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=40

Teapo caps aren't that bad, they're better than some of the other cheap Chinese brands. Main thing is that caps age and cheaper caps will age quicker. That PSU also had some ripple issues. These issues will only get worse with age.

orestesp · 25 Aug 2017 at 23:21

Borealis said:
It won't fry anything. Using 2 6-pin to single 8-pin has been around for a long time. Some cards still come with the adaptor.

Hard to say what's worse, the Silverstone or the VS550. The VS series are cheap units using some budget parts. They're the cheapest Corsair PSUs available. Personally I would use neither, as the PSU is arguably the most important component in the system but if I had to choose, I'd go with the VS. as it's newer.

If this is the correct model, here's a review. Page 4 is disassembly showing the internals:
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=40

Teapo caps aren't that bad, they're better than some of the other cheap Chinese brands. Main thing is that caps age and cheaper caps will age quicker. That PSU also had some ripple issues. These issues will only get worse with age.

I heard that Teapo caps just don't like heat, which shouldn't be an issue in my case (rated for 85C instead of the usual 105C).
The PSU probably wasn't even used that much in that old system (it had an entry level C2Q with some random passively-cooled gpu).

Is it that bad?
What's the worse thing that could happen and how possible is it?

Borealis · 26 Aug 2017 at 00:17

Worst case scenario is that something lets go on the secondary side and fries some of your components, usually the motherboard or GPU. If something goes on the primary side, your componets are usually safer. To clarify, neither unit is in the same category as CiT junk/no-name firebombs. That is a whole different level of junk. Although it's not ideal, the VS550 should be able to happily power that system. Long-term I'd plan to budget to upgrade the PSU. A high quality PSU can be re-used and last you for several builds.

Ripple is an issue if it goes out of the ATX spec. High ripple has the potential to damage your components.

orestesp · 26 Aug 2017 at 08:28

Hopes and dreams ruined.
Any particular SuperFlower PSU that you'd suggest for my build? I'll probably have to buy it from somewhere like Amazon since they don't have it in my country.

Thank you for your time.

Borealis · 26 Aug 2017 at 17:03

Any of these would be a good choice:

https://www.overclockers.co.uk/supe...us-platinum-power-supply-black-ca-056-sf.html
https://www.overclockers.co.uk/cors...lar-power-supply-cp-9020133-uk-ca-233-cs.html
https://www.overclockers.co.uk/evga...plus-gold-modular-power-supply-ca-023-ea.html
https://www.overclockers.co.uk/seas...plus-gold-modular-power-supply-ca-05p-ss.html

Reviews of the Focus Gold and TX here:
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=528
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=529

If you can afford it, my preference would be the Seasonic Focus Gold. It's a new Seasonic product and gets a good write up. It's marginbally more expensive than the excellent EVGA Gs550W, which is also built by Seasonic. The SF Platinum King is a rock solid PSU but it isn't modular. The Corsair TX is also a good unit, but it is only partially modular.

For the time being by all means run your system using the VS550 while you save up for a better PSU. As long as you're not overclocking, it'll be fine for now.