Mulit Radeon VEGA rendering build - WIP

Thanks @Retrotrollet for some inspiration to actually get my project finished.

My Goal is a multi AMD Radeon Vega build.

Over 2020 i’ve been purchaisng all the parts (GPUs, water blocks, etc). But its time to get my lazy ass back to work.

First, all VEGA’s will not run at stock, but actually underclocked to consume a more respectable power. Goal is to power the 8 Vega’s via single Seasonic 1300W Platinum PSU (CPU/system on another Seasonic PSU)

Inital test

Vega 56 - air cooled - running on PCIe 8x extender and motherboard bifurificaiton (PCIe lane splitting) on Threadripper 1950x system.

Using the “power saver bois” (bios switch towards the displayport connectors) and various settings available in Radeon software.

Based on below will target the the 100-150W range.

Below is 2BMW default render scene. will test classroom scene later as well.

GPU BIOS Preset Option Target Clock Clock Power (peek) PSU efficency Power (adjust) BMW 2 (m:ss) BMW 2 (s) W/s s/W
VEGA56 Back Preset Balanced n/a 1600 215 0.93 199.95 1.29 89 2.247 0.445
VEGA56 Back Preset PowerSaver n/a 1580 210 0.93 195.30 1.30 90 2.170 0.461
VEGA56 Back Auto Undervolt n/a 1580 194 0.92 178.48 1.30 90 1.983 0.504
VEGA56 Back Auto Overclock n/a 1600 230 0.93 213.90 1.29 89 2.403 0.416
VEGA56 Back n/a Manual Max 1590 1580 230 0.93 213.90 1.29 89 2.403 0.416
VEGA56 Back n/a Manual Max 1538 1520 210 0.93 195.30 1.31 91 2.146 0.466
VEGA56 Back n/a Manual Max 1474 1435 180 0.92 165.60 1.35 95 1.743 0.574
VEGA56 Back n/a Manual Max 1312 1305 148 0.92 136.16 1.41 101 1.348 0.742
VEGA56 Back n/a Manual Max 1269 1260 128 0.92 117.76 1.44 104 1.132 0.883
VEGA56 Back n/a Manual Max 1138 1133 122 0.91 111.02 1.53 113 0.982 1.018
VEGA56 Back n/a Manual Max 991 988 114 0.91 103.74 2.06 126 0.823 1.215
VEGA56 Back n/a Manual Max 852 850 106 0.91 96.46 2.22 142 0.679 1.472
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Holy cool,more pics.

So far only 3 GPU’s

ONe Vega 64 is on shared PSU with the system as such not included in Power measurements (will update if that changes)

The otehr two are on seprate PSU - Seasonic 1300 Platinum

VEGA TIME On Seasonic PSU On Seasonic PSU Excluded from power measurements Power not including Main Vega64 - on different PSU
Setup # Vega56 # Vega64 Main Vega64 Power (w) Time (m.ss)
Stock 1 . . 210 1.30
Stock . 1 . 240 1.20
/Stock/ 1 1 . /450/ 0.45
Stock . 1 1 240 0.43
Stock 1 1 1 450 0.33
1401-1474 1 1 1 300 0.36
/1401-1474/ 1 1 . /310/ 0.50
1401-1474 . 1 1 140 0.48
/1300/ 1 1 . /280/ 0.52
1300 . 1 1 135 0.51
1300 1 1 1 280 0.37

Changing clocks form stock (about 1600) to predefined 1400 (+/-), power droped by 140W, and lost about 5 seconds.

[Update] Setting to 1300, dropped by additional 30w, and lost another 2 seconds…

But all 3… surprisingly form 33s to 37s… so about 10% slower …

This the inital test… more to come as I connect more GPU’s. Two Vega’s are running form single PCIE slot via PCIe Bifurification. one getting 4x pcie and second one getting 8x pcie. :slight_smile:

Bad at taking pictures… and this is a very “janky” “flaky” "… disaster waiting to happen, setup. luckily no leaks.

More to come as I develop a good mounting system in my desk.

You are on your way to finish the build slight_smile:

No chance.

  1. OpenCL development is simply behind on optimizations - understandable as most users have Nvidia GPU’s but still.

  2. even using 12 GPu’s (if scaling is 100%) i can only get down to 7.5 seconds.

E-Cycles is simply well done, no competition there. though i guess that also boosts AMD gpus but 10-20%… will give it a go and compare.

Still your 3 seconds… nope…

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