The hyperthreading has some shared resources in each core which can cause contention in heavy workloads. It's probably better to have faster cores for folding as some units max out my 3.4ghz system while others don't.

Cool GTX

Chris21010F@H you should disable it. its just like gaming in that the extra overhead to make the extra virtual cores will actually hurt PPD

 
You disabled HT in the BIOS ? 
 
I'm not using the CPU to Fold or Crunch; just enjoying the 4 GPUs churning out the PPD

correct it is under your motherboard bios. now by hurt PPD i mean only a couple percent, not a whole lot. (here is my source) F@H is an instance that needs faster single cores and not many slower cores, which is what hyper threading kinda does.

Cool GTX

bcavnaugh
 
One Thread Per GPU will also works when HT is turned on.

HT ?

Hyper-threading
The only project and is not Folding is LLR under PrmeGrid and it likes to have HT Turned Off when running.

Chris21010

Cool GTX
Where are you posting your "Case issue" video and the above mentioned video when done?

i do not have a PC that can handle video editing until i finish the build, kinda a catch-22 there.
 

Cool GTX
HT ?

that is Hyper-Threading, a way intel makes 2 virtual cores for every single core on the chip. as for HT and F@H you should disable it. its just like gaming in that the extra overhead to make the extra virtual cores will actually hurt PPD, if you have a x8 or x16 pci-e lane GPU that is. in Ali man's particular use case with only a 4 core system and trying to run 5 GPU's on a bottle necked pci-e bus having HT enabled actually helps him. because with it that 5th FahCore21.exe instance doesn't have to fight for CPU time.

"as for HT and F@H you should disable"
Chris21010 Not true at all then Folding only on the GPU or for that mater when Folding on Both The CPU and the GPU at the same time.
 
This is going to Confuse New Folding Users!
 
 
From https://folding.stanford.edu/home/faq/faq-smp/#ntoc6

What about hyperthreading?

Hyperthreading is a technology used on Intel CPUs to improve parallelization of computations. A dual-core CPU with hyperthreading enabled appears to the operating system as a four-core CPU. Each physical core powers two logical cores, so in reality hyperthreading does not actually double the CPU’s performance. Hyperthreading is usually enabled in the BIOS by default, and we recommend that it stays enabled, as the SMP cores can use it to process Work Units faster.
 
From https://folding.stanford.edu/home/faq/faq-smp/#ntoc7 

What about using both SMP and GPUs?

GPUs can also be used to process a separate FAH assignment while running SMP (see the GPU FAQs) but some CPU processing is required to support that GPU. If you also process with a GPU from AMD, that GPU support function consumes one CPU core and less is available for SMP processing. You can expect to higher SMP performance by dedicating fewer CPU-cores to SMP to avoid resource conflicts. NVIDIA GPUs do not currently require a full CPU’s resources.
 
 (here is my source) Gaming and Folding are like Apples and Oranges. Folding uses FPU and FPU run better with HT On.
 
 
From Link Dated Feb 2015
Except for the synchronization issues, hyperthreading can increase performance somewhat.  A pair threads share the same FPU, so if that pair is idle, it will produce about 120% as much as the same (idle) non-hyperthreaded FPU.
 
https://bitsum.com/pl_when_hyperthreading_hurts.php
 
I would say on your Rig New 5 GPU's 1 PC Build  having HT Turned Off in the Bios may be best for you.
99.9% of Folders are not Folding 7x24x365 and at least 25% also run BOINC Projects that very much need and use HT to run Projects.
Except as stated above LLR Projects from PrimeGrid.
 
Since the floating point operations are the key to throughput, hyperthreading really only gives you 10-15% more work completed 
 
Very good Reading: An Empirical Study of Hyper-Threading in High Performance Computing Clusters

interesting but old and outdated information pertaining to dual core CPU's if you have a newer generation 6+ core i7 hyper threading doesn't do anything for you. as FahCore21.exe is not a process that benefits from improved parallelization, its a very single threaded process. quad core CPU's are on the borderline if it helps or not so i would leave it on, just so windows and other processes have some breathing room if you are folding with more than 1 GPU. i guess i should have clarified that tiny tidbit of information. you do not always turn HT off for every use case, just if you have more than 4 physical cores on your CPU or if your machine is doing nothing but GPU folding.

Welp i got the flex tubing installed and added a little green dye so i can see if it leacks and now i wait for 2 hours and then connect everything and then try and boot... i hope i didnt kill anything durring this rebuild.

How much rad space is that to cool those 5 cards?

parts list say two EK 420mm rads, equivalent of 8x 120mm rads. 
 
Also i am running and everything is working BUT EVGA Precision will not work past 4 GPU's, bummer  will have to get EVGA to patch me in or i'll have to try other software. temps are OK, ambient air temp is ~26, liquid is 38C after 5-7 min of folding, GPU's range from 44-53C big range here, and CPU is 50C. just wish i could OC these things and really push them to their limits...
 
note: temps drop 4C after removing the right panel with air filter completely. this allows much more air into the intake 420mm radiator.
 

 
EDIT: oh and i am not pulling but ~900W from the wall, CRAZY
 

Awesome build! One question though. How are those Corsair ML 140 fans working out for you? I know they are supposed to be very silent but how is the cooling and air flow?
 
I was thinking of getting a couple to replace some fans in my current rig. 

44-53C is a super big range, I'd say something is not right since they all are in parallel?