Major difference between benchmark values and real values on RTX4090 rig

[electronos]

benchmark is your theoretical maxspeed, depending on hash and input you can provide 

for fast hashes like md5 this can be a hard task, especially when having 8 cards, see wiki for more infos

https://hashcat.net/wiki/doku.php?id=fre...full_speed

in your case i would assume providing each card with a uniq mask on their own will result in a better performance as now the passwords candidates are generated and splitted to your cards
OR
regarding your posted infos i would do a test-run with your mask and only 3-4 cards, maybe this way you will get closer to your maximum per card and you have the other 4 free to do another mask or job

and for timeout, yeah please install the patch as mentioned

https://hashcat.net/q/timeoutpatch

Thanks for advise . I wonder if i do as you said (using 4 instead of 8 GPUs) is there any sufficient way to cluster 2 or more rigs in any way to do a cracking process simultaneously on them ? or somehow break the work to make it done by 2 rigs ? My attack type is -a 3 at the most of the times . Thanks