Helping thread :)

[FitGirl]

The example string works just fine
srep+4x4:t4:b128m:lzma:128m

Never use large dict size for 4x4
4x4 means you're running 4 instances of LZMA, each with 400Mb dict size, that leads to 400*4*11 = 17600 MB of RAM to compress.

On user machine ISDone will require four continuous memory blocks of 400 MB each.

Also, using 4x4 hurts compression ratio due to blocking. That's why "some guy" repacks are larger than any other. You can try to use LZMA2 instead of LZMA1 (gives you 2 decompression threads by default), but it has it's own downsides.

I've personally used 4x4:LZMA in some of my early repacks, but gave it up. Number of SSD users is not that high, and unpacking in four streams on HDD often leads to overload.