md5 bruteforce with 2 known salts

[AlanGomes_]

Given a known left salt and right salt, how can I bruteforce a md5 hash with a unknown password between them? For example:

md5($salt1 . $password . $salt2)

$salt1 is known
$salt2 is known too
$password is unknown and needs to be bruteforced (unknown length and unknown charset)

I tried using a mask attack but the performance wasn't so great.

Mask:

Code:

?a,SALT1_EXAMPLE?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1?1?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1?1?1?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1?1?1?1?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1?1?1?1?1?1?1SALT2_EXAMPLE
?a,SALT1_EXAMPLE?1?1?1?1?1?1?1?1?1?1SALT2_EXAMPLE

Command:

Code:

hashcat -m 0 -a 3 -w 3 --force --opencl-device-types 1,2 test.hash mask.txt

Speed of this method in a RTX 2060 Super:

Code:

Time.Started.....: Wed Dec 16 19:35:52 2020 (26 mins, 31 secs)
Time.Estimated...: Wed Dec 23 08:44:37 2020 (6 days, 12 hours)
Speed.#1.........:  123.4 MH/s (4.53ms) @ Accel:256 Loops:1 Thr:256 Vec:1

I was expecting something close to 12940.3 MH/s (as performed in benchmark mode)

Can someone guide me in how to perform this in hashcat?

Thanks in advance!