Question Will a Thermaltake 750p (sp-750ah3ncb-a) work with 3070 founders edition?

ljay880

Distinguished
Oct 1, 2009
31
0
18,530
0
Hello everyone, putting together a build for my son and was curious if this PSU would work. I've built a few pcs, but never something for gaming, and this psu has 4 pci-e 6+2 pin connectors. The gpu needs a 12 pin, which this psu doesn't have, but the gpu comes with an 8pin to 12pin adapter. I assume I can just use one of the 6+2 pci-e cables for this, but wanted to ask first as I am not knowledgeable about the voltages, and wouldn't want start a fire or short out anything. I know the psu is older, but was only use for about 3 years before sitting on the shelf for a long while. I was hoping someone could look at the specs for the psu and let me know if it's safe and will work. Oddly enough, the included gpu adapter only has pins on 6 of the 12 pins, on the 12 pin side .. makes me nervous, but not sure if I have any reason to be.
Thanks in advance!
 

Karadjgne

Titan
Ambassador
That's a TT Smart 750w Bronze. It's as bad as it gets in TT's lineup, and while having the right 4x 6+2pin pcie, it's really not designed for the stresses a high current gpu like the 3070 can demand.

To put it in car terms, it's a Crown Vic, not a Mustang. Both might have the same 8cyl 302, but one is designed for grandpa and his driving habits, the other for the grandson and his driving habits.

Capacitors are the major component electrically inside a psu. If you think of a capacitor in terms of a florescent light bulb, they are extremely similar. The more use it sees, the faster the end turns purple and eventually quits. But if the light is not used, it'll last for years and never turn purple. You have 3 years on an office psu. No worries. Doesn't really matter how long it sat on the shelf. That's not what makes those caps go bad.

It's a serviceable psu that'd go very well in a normal use, office type pc, but won't handle the instant high stop/go/stop/go that a gaming gpu can demand. It'll last a while, but how long generally depends on the loads the gpu is seeing. Could be a day, could be a year, could be more.

Older gpus used a 6pin or 6+2pin or combination depending on actual power draw. The 30 series saw the release of a 12pin to take the place of a 6+2 or 6+6 or 6+8 or 8+8 design, which is why they supplied the adapter. That adapter matches up with that gpu, no other. Having pins missing wires just means it's a power limited card, and doesn't require more pins populated, but still uses the same 12pin junction. It's a money saver, all the 30 series use the same connectors instead of using different styles for 6, 6+2, 8+6 etc.

It's technically possible to provide upto 720w with 4x 8pin pcie plugged into a 4x8 to 12pin adapter. Pcie is restricted to 60w per pin, the adapter and gpu isn't. The 3070 FE is @ 220w so won't require every power pin populated in that 12pin.
 
Last edited:
Reactions: ljay880

DSzymborski

Titan
Moderator
I'm not quite as negative about the PSU as Karadjgne, since this is a rare exception for the SMART PSU series in that isn't a garbage-tier Sirfa with a couple new stickers thrown on. It isn't even group regulated! But I'd hardly call it a good PSU, either, and I would absolutely not use it with a 30-series card. Not to mention it's ancient. For 3070 and above, it's a top-tier PSU or bust as these GPUs put a lot of strain on their power sources.

I'm even more negative about a PSU of this type that's sat around for years. That this wouldn't be conditioned after years of the capacitors just sitting around and degrading creates an initial period of much increased danger as well.
 
Reactions: ljay880

ljay880

Distinguished
Oct 1, 2009
31
0
18,530
0
Thank you both for the information. It sounds like a gamble on how long it will last. I put together the pc ( test bench, no case or gpu) and had it on for about an hour. If the power supply dies, will the rest of the components be OK? I've had psus die before, never taking other hardware out with them, but have heard the horror stories. I wasn't sure if some had protections built in, and if so, how this one might do? I plan to get another psu, but funding is currently low from buying the rest of the parts.
 

DSzymborski

Titan
Moderator
Thank you both for the information. It sounds like a gamble on how long it will last. I put together the pc ( test bench, no case or gpu) and had it on for about an hour. If the power supply dies, will the rest of the components be OK? I've had psus die before, never taking other hardware out with them, but have heard the horror stories. I wasn't sure if some had protections built in, and if so, how this one might do? I plan to get another psu, but funding is currently low from buying the rest of the parts.
It's a roll of the dice.

I'm not sure why the GPU was purchased before the power supply to safely power it. The price of the sports car must include the cost of the insurance and maintenance.
 
Reactions: Karadjgne

Karadjgne

Titan
Ambassador
Look up MSI Kombuster. It's a very decent gpu buster program because it covers a variety of tasks. If you test bench that psu, run All of the tests as that'll punish the gpu in a variety of tasks, not just a singular task.

Transient loads happen when there's a high use of 3.3v and 5v, and then a 12v demand is introduced. Or. There's high 12v use and a 3.3v or 5v demand is introduced. The second being most common since hdds, usb, Sata etc all use 5v. There you are, heavily gaming, and the game pulls an autosave or hdd does a smart check etc and 'poof' shutdown and you are clueless as to the cause.

Apart from regular draw, it'll be the transient loads that can break that psu. Maybe not permanently, but often enough that trying to game on a pc that periodically just suddenly and instantly shuts off becomes a lesson in frustration management.
 

ASK THE COMMUNITY

TRENDING THREADS