Dual 4090 rig build

[Grimmbeaver]

Is it feasable to build a gaming rig that I can use to also Crack hashes?  I currently have an Alienware R12 with a single 3080 GPU... I get about 960ish kh when messing with 22000 wifi hashes. I purchased it duriing the height of the pandemic as it was the only way to secure a rtx3080 at the time.  I hate it...it's noisy and ugly. 

MSI has some liquid cooled rtx 4090s that look interesting...the Nvida founders edition is a blower style card as well. 

Thoughts?  There's several mobos that appear to offer support for two rtx 4090 GPUs.

I'm a super noob with hash cracking ribs, I've read the excellent guide at password village... which is why I'm asking for build guidance from experienced members.  Is a hybrid dual rtx4090 gaming/hash rig crazy?

Regards
Grimm

[marc1n]

The electricity consumption will be crazy, unless you have it for free. Better get a rig on vast dot ai.

[Grimmbeaver]

The electricity consumption will be crazy, unless you have it for free. Better get a rig on vast dot ai.

I'm not concerned about the power consumption as I live off the grid and produce way more power then I can use.  I'm also not sure what uou mean by "vast dot ai" 
Apologies I'm just starting with hashcracking and I'm not familiar with most of the terms and or abbreviations. Also thanks for taking the time to respond... lol you're the only one that did. 

Grimm

[slyexe]

Theres no issues with building a cracking station with 2x 4090's. Everything you need to know is that cooling is important, build to be able to expand, and the rule of thumb is RAM=>VRAM.

I am currently using a setup involving 4x 3090's and have no issues, 4090's would be equally the same in space consumption and slightly higher power draw. 4x cards on a single 120VAC 20amp circuit, just do the math. 400-450W per card, 120VAC *20 = 2400 MAX Watts subtract 15% for extremities (PSU AC to DC conversion, breaker capacity relating to heat in the summer vrs winter, etc. etc.) leaves you with 2040W total wattage on that breaker. Using 220VAC would be more efficient however it isn't always accessible for everyone's scenario.

So 4x 450W 1800W Card consumption
Add 150W for CPU, HDD, MOBO
Add 150W for external cooling
And I am at my threshold.

As for cards, use your discretion, in my opinion closed loop liquid cooling is a lot more prone to failure than just a fan but that's only my opinion.

In regards to Marc1n, he is relating to renting cloud computing rather than creating your own crack station.

[abidmaria]

Theres no issues with building a cracking station with 2x 4090's. Everything you need to know is that cooling is important, build to be able to expand, and the rule of thumb is RAM=>VRAM.

I am currently using a setup involving 4x 3090's and have no issues, 4090's would be equally the same in space consumption and slightly higher power draw. 4x cards on a single 120VAC 20amp circuit, just do the math. 400-450W per card, 120VAC *20 = 2400 MAX Watts subtract 15% for extremities (PSU AC to DC conversion, breaker capacity relating to heat in the summer vrs winter, etc. etc.) leaves you with  2040W total wattage on that breaker. Using 220VAC would be more efficient however it isn't always accessible for everyone's scenario.

So 4x 450W 1800W Card consumption
Add 150W for CPU, HDD, MOBO
Add 150W for external cooling
And I am at my threshold.

As for cards, use your discretion, in my opinion closed loop liquid cooling is a lot more prone to failure than just a fan but that's only my opinion. 

In regards to Marc1n, he is relating to renting cloud computing rather than creating your own crack station.

Hello , in that case how long it takes for you (time) to crack a password as per the below formula :

hashcat -m 22000 -a 3 hash.hc22000 ?a?a?a?a?a?a?a?a

Thanks

[slyexe]

Hello , in that case how long it takes for you (time) to crack a password as per the below formula :

hashcat -m 22000 -a 3 hash.hc22000 ?a?a?a?a?a?a?a?a

Thanks

Dude theres several benchmarks online, just look and do the math yourself lol. 

https://gist.github.com/Chick3nman/e4fce...2106d73fef


8^95 / 1,100,000

[TickleMyPickle69]

Theres no issues with building a cracking station with 2x 4090's. Everything you need to know is that cooling is important, build to be able to expand, and the rule of thumb is RAM=>VRAM.

I am currently using a setup involving 4x 3090's and have no issues, 4090's would be equally the same in space consumption and slightly higher power draw. 4x cards on a single 120VAC 20amp circuit, just do the math. 400-450W per card, 120VAC *20 = 2400 MAX Watts subtract 15% for extremities (PSU AC to DC conversion, breaker capacity relating to heat in the summer vrs winter, etc. etc.) leaves you with  2040W total wattage on that breaker. Using 220VAC would be more efficient however it isn't always accessible for everyone's scenario.

So 4x 450W 1800W Card consumption
Add 150W for CPU, HDD, MOBO
Add 150W for external cooling
And I am at my threshold.

As for cards, use your discretion, in my opinion closed loop liquid cooling is a lot more prone to failure than just a fan but that's only my opinion. 

In regards to Marc1n, he is relating to renting cloud computing rather than creating your own crack station.

Hello , in that case how long it takes for you (time) to crack a password as per the below formula :

hashcat -m 22000 -a 3 hash.hc22000 ?a?a?a?a?a?a?a?a

Thanks

You could very quickly crack a 22000 hash with a SINGLE 4090, if all you're going to attempt to crack is 22000 then stick with your current 3080 GPU, unless you're really looking to justify that next gen upgrade