Clarification on New V12 Compression Algorithm

[bbuchanan]

In the "What's New" document there a blurb on the new High and Extreme compression algorithm.

The first sentence says the new algorithm increases restore performances by up to 2x (takes half the time), but the latter summary of High and Extreme both say it's 2x slower (twice the time). Am I just reading this wrong?

https://www.veeam.com/veeam_backup_12_0 ... new_wn.pdf

New compression algorithm — The new algorithm behind High and Extreme compression levels
improves data reduction ratios by up to 20%, lowers CPU usage by up to 3x and increases
restore performance by up to 2x over the previously used one. Compared to the default Optimal
compression algorithm, which remains unchanged in V12, High compression now provides up to
20% (OS disks) and 60% (database disks) more data reduction at the cost of 2x CPU usage and
2x slower restores. Extreme compression provides up to 25% (OS disk) and 80% (database disk)
better data reduction at the cost of 10x CPU usage and 2x slower restores

[doktornotor]

Let's try the other way round: Previous High/Extreme have up to 2x slower restore when compared to the new algo with identical (High/Extreme) settings. The rest of the "blurb" compares Optimal vs. High/Extreme.

[Gostev]

That is correct, doktornotor is spot on.

So with the old algorithm, restores from backups with High/Extreme compression were up to 4 times slower than from backups with Optimal compression... and with the new algorithm, restores are only 2 times slower.

[vmtech123]

2x faster than previously used algorithm

High compression is 2x slower than Optimal compression
Extreme will be slower than that

Key take away, use Optimal or defaults unless you have data you KNOW is going to get really good compression.