PSU buzzing, Palit GTX970 JetStream eGPU setup based on Akitio Thunder 2

[El_Febio]

Hi guys,

I'm new to this forum, Mac world and also to eGPU world! So I decided the better thing to do is to put my hands right into the mud..

I purchased an used, original Akitio, a Palit GTX970 JetStream and a cheap Micro ATX PSU (Vultech GS500M) - My pc is a mid 2014 MacBook Retina with Windows 10 and Sierra (I5 2.6 GHz, 8Gb RAM, Intel Iris 5100, 256Gb SSD).

First thing first, I prepared the PSU to power all the things.

The datasheet says it is a 500w, with two 12v rails, 29A total (348w). I cut all the connectors, isolated the other lines I won't use (3.3, 5v, 5vsb and -12v), shorted the power on with a negative. Then I had six 12v positives, and all the commons. I gathered 4 wires and solder them to the positive of the two PCI 6 pin cables, same I did for the negatives, except two.

I used the remaining wires (2 positives and 2 negatives) to make the barrel connection for the akitio.

Tested without anything plugged, it works (fan spinning)

Then I build a plexiglass enclosure to contain everything, i kept the layout of the original metal case, so the position of the board is the same; next to the video card, on the opposite wall I planned to install the psu, with the air intake obvously facing the outside, and the air output in the rear. In the front I installed a 120mm fan, plugged into the fan port of the Akitio board.

I partially assembled all the parts, leaving the top and the right side (opposite to the board, to be clear), and power on.

Surprisingly, nothing blew up... I managed to make the card recognized by Windows, installed the drivers, AND make some gaming - benchmark test to test the setup.

I made a short session of Farming Simulator 2015 and suddenly nothing wrong .. BUT .. after some minutes the PSU started to buzz. The more the card required power (by doing some "complex" tasks), the more PSU buzzed. I also tested with Unigine Valley, in ultra setup. Everything worked, I made two benchmarks, I reached 85°C on the GPU and 96° (WOW..) on the CPU..

And now.. my concerns..

- is the PSU buzzing just because is sh*tty? Or I made some terrible mistake by wiring, soldering and so? I took a look inside it and TBH.. even if I don't know electronics so deep to reverse engineering I noticed that 12v wires come ALL from the same pad on the pcb.. so I guess it's not a problem to put them together. If the power table is correct .. I should get nearly 350 w from the 12v line .. during the benchs I logged the power consumption with HWINFO, and the 970 drew about 120w on its peak .. if summed with the Akitio I get less then 200w .. far more behind the limit..

- the temperatures .. ok 85° in full load would not scare me if the GTX was inside my good old desktop gaming rig .. but here I think the game is different, is there any risk to "cook" the Akitio Board? The space between the card and the board is really low (I'm not using a riser), I'm thinking about improving the ventilation by drilling many holes in the wall very next to the board, and maybe installing a more efficient fan connected directly to the 12v. Would it be ok?

- the riser .. TBH I don't really know if I need the riser or not. By now the card is plugged directly into the Akitio Board, powered by the buzzing PSU, that also power the board. Everything works even if the mentioned troubles above.

Any kind of suggestion is accepted, last things to say, I'm quite able to solder and etcetera. I own also a Dell DA2, but I preferred to make an "everything integrated" solution and last but not least .. JetStream GTX970 on review peaked quite 200w itself. I need more power, I guess.

Ok I'm risking to be lynched .. but just to know .. I decided to mod directly the PSU by following a guide taken on the web .. stupid or not it's not my invention

I attach a pic of the connection I made, of the PSU board and the power table

 

 

Here are some pics of my setup .. on idle and with low gpu load it's running fine, no buzz BUT no load .. tested again Unigine and here are the results (AGAIN the psu is buzzing).

Respect to the post I modified the case by drilling holes behind the Akitio Board, drilling the psu case, and most important, I dressed the power wires of the akitio board with a silicone-fiberglass sheath to protect it from the heat produced by the gpu.

Again, thanks.. any hint would be appreciated.

 

[Dschijn]

GTX 9x0 and 10x0 cards will create buzzing on the card or PSU very often.

 

unfortunately this is normal

[El_Febio]

28 minutes ago, Dschijn said:

GTX 9x0 and 10x0 cards will create buzzing on the card or PSU very often.

 

unfortunately this is normal

  really?! So it's useless to try with a better PSU? Is the DELL DA2 insuficient?

By your competence, is anything wrong with the entire setup?

Thank you

[bloodhawk]

12 hours ago, Dschijn said:

GTX 9x0 and 10x0 cards will create buzzing on the card or PSU very often.

 

unfortunately this is normal

The buzzing from the cards us called coil whine. 

I haven't experienced any from PSUs.. yet. 

[Tech Inferno Fan]

I've used those common 12V/14A + 12V/15A PSUs before and too noticed PSU buzz under load. It was very prominent during testing of 3dmark vantage and would occasional switch off - the overload protection kicking in. 

 

Very questionable whether they can deliver the specified power and maintain longevity.  Jetstream GTX970 is one of the performance cards with higher power consumption.

 

The solution here is to get a quality replacement PSU.

[El_Febio]

I've used those common 12V/14A + 12V/15A PSUs before and too noticed PSU buzz under load. It was very prominent during testing of 3dmark vantage and would occasional switch off - the overload protection kicking
 

The solution here is to get a quality replacement PSU.

This is right my case. So I have to get a better PSU. I think I'll go for a BeQuiet SFX 450w, by now it's the better quality/price I found.
But.. why this is happening? In my case -like I said- I didn't found evidence of two separate 12v lines, they come right from the same welding pad on the pcb. The total amperage should drive everything without problems.
Last but non least.. shall I have to consider the split lines on the new psu? Better single or multi rail? Are there difference in the connection I will make in function of this?
Sorry about the amount of questions and thank you and to the other contributors



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[Dschijn]

I had 5 different 970 one 980Ti and now a1080. All had coil whine/buzzing. Even high end PSUs will not help.

The Problem are the coils on the GPUs.

[El_Febio]

Even high end PSUs will not help.

The Problem are the coils on the GPUs.

Wow.. I'm going to buy a Silverstone or a Chieftech gold 80+.. shall I left them where they are?

Another thing.. not inherent to PSU.. my CPU temp in game is stable @ 90* C.. in Windows, with internal monitor.. is it normal?


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[Dschijn]

90C is good

[El_Febio]

90C is good [emoji6]

Ok so I'll go in peace with the cpu temp.

I think I'll give a try to a better psu, hope that helps with the noise.

I purchased two pwm corsair fans (the sp120l, adopted by h100i) and a temperature regulated controller, whose sensor I'm going to put between the gpu and the akitio board.
I think I'll set the fork at 50-70º C or maybe 40-60.. gotta do some trials

Will keep up to date also with some pics


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