trying to post the other pictures. going to install it tomorrow

I don't plan to use the included paste which came in a little plastic bag, not a syringe. I'm guessing they don't expect anyone to use it lol. I plan to use thermal grizzly. I didn't spend too much time inspecting the assembly parts like thermal pads etc. The cooler does seem well made.  I'm impessed for the price. 

Lord Winchester
Is there no backplate on the barrow Block? 
Remember, the 3090 got plenty of VRAM that needs cooling on the backside of the Pcb. 

It allows for the use of the stock backplate which is awesome if you ask me, the stock backplate looks badass.

Razgriz2006
Dont do it!. I have been suffering with this block for a week.

what are you suffering from?

Sorry for the unfocused backplate pick. I wasn't aware it was blurry.
 

 

 

 

There were a few things that made this installation unnecessarily difficult. 
 
1) The instructions are garbage because the instructions that came with the waterblock were just generic instructions for any card. I looked on barrow's website and they have dedicated instructions but are still not good. I found a few helpful things like thermal pad placement. Doesn't show replacing any thermal pads onto the back plate.
 

 

 
2)The instructions were unclear which screws to use. I ended up using spring screws with the clear washers only where the waterblock attaches to the board. I believe there were 9 in total but i'm not 100% positive.
 
3)If you look at the picture above, it shows thin blue strips that they say NEED to be cut to size. They do not supply you with the narrow strips to cut so you would have to cut the wide blue strips to fit a small strip. I left the stock thin evga pads in instead but used the full size blue where indicated. I didn't want to deal with attempting to cut thin long strips and the evga thermal pads seemed to be super soft high quality. 
 
4)The backplate - I left the backplate thermal pads in tack instead of replacing them. If i replaced them with the supplied blue pads, they might have worked but i didn't want to chance it. As a side effect due to using the original pads, the black spacers are not big enough to allow the corners of the back plate to be tightened down a lot. I'm not entirely sure using the blue strips would rectify this issue. If you tighten the corners down, the middle of the backplate will bow and the thermal pads will not make contact correctly with the memory. You have to be extra careful when tightening the corners down and not tightening them too much.
 
After all that is said and done I used a ek water leak tester and left it for 40 minutes. No leaks so that's good. 
 
looking at the mem temps, I'm surprised that there's a decent temp difference between the memory and the gpu. gpu2 is showing similar temps to the memory which makes me wonder if it's due to the supplied thermal pads. I haven't researched what others are reporting with other waterblocks so idk if this is normal or not. Overall I see a 10c drop in mem temps over the stock ftw3 ultra cooler set to 90% fan speed.
 
If I were to do this again, I probably wouldn't buy this kit UNLESS I desperately wanted to keep the factory back plate which I wanted to do. I wish I had the patience to have waited for the heatkiller.   
 
 
 
 

 

 
Ran Port Royal for 20 minutes to get a heat soak temps with a OC of +500 mem +120 gpu and 119% power limit.

I'd rather not tear down the card again. The temps seem to be in line with my brothers corsair hydro-x waterblock on his founders 3090. I was trying to find memory temp reading on the ek block and Optimus but haven't seen anyone post anything on these forums. I did see someone posting in the active backplate mod and those temps were in the low 70's. I'm contemplating attaching a 120 fan to the backplate since the backplate has plenty of holes in it, it may help drop mem temps a few degrees more. I was actually going to attach a cpu waterblock i had laying around to the back plate but decided against doing it. Maybe i'll do that. 
 
I also have a flir infrared camera attachment but it's micro usb so i have to find my old phone so I can take a few pictures to see if there's any hot spots. 

 
 

fps_noob
How's the overclocking performance with it? I'm currently waiting for an EK block for my 3080 ftw3, but it's not expected to ship until April...

The last three pics were with a +120 gpu +500 mem and power limit set to 119% with port royal and a heat soak. I haven't really attempted to OC the card other than those adjustments.
 
If you want to get the EK and you're in the US, I would suggest setting up distillio and have it watch the "no stock" on performancepc website. I've seen them come in stock. 
 
I was told when I purchased the barrow that there was very large demand for it and that I ordered early before others so I got in the first batch before the chinese new year.( February 5th to 22nd) IDK how true that is but it took a few weeks from purchasing to shipping and arriving. I would factor that into your decision making and contact whomever you plan to buy it from beforehand to see if they actually have it in stock.

Nice pics! Be careful about screwing into your back plate for short reasons and for resale reasons.
 
Your pics have me reconsidering going backplate-less

I love barrow fittings but I'd be uncomfortable to use a block which bends the PCB that much

Pennywise359
I love barrow fittings but I'd be uncomfortable to use a block which bends the PCB that much

Actually after looking at it a bit more, that screw is not attached to the back plate nor the waterblock. I'll see if i can loosen it over the weekend. I think it's actually what's effecting PWR5 temp difference. 

Optimus water block
 
Spent four hours last night playing Red Dead Redemption 2, 4k, most settings Ultra.
3090 FTW3 +300mem, +150 clock
Ryzen 5900x, PBO off, no overclock

HWINFO averages over that four hour period...

Memory Junction - 50
GPU1 - 34
GPU2 - 42

PWR1 - 42
PWR2 - 42
PWR3 - 42
PWR4 - 46
PWR5 - 42

MEM1 - 45
MEM2 - 42
MEM3 - 40

Realize we are not directly comparable because full coverage block vs Hybrid Kingpin, but, figured I'd drop this for temp comparisons...
 
You can probably drop temps on your VRMs by doing some pads on the backside of them... you would also drop further with some heatsinks on the backplate:
 

 
It's interesting that the PWR/VRM temps are so different between the two cards in general, PWR4 is the warmest on the 3090 FTW3 types, whereas on the Kingpin it's PWR3.