Hey guys, if you are installing Mac OS High Sierra on a SSD, then format the SSD in APFS( Apple File System!). It works like a charm. APFS is the new update after Journaled. And it is specifically and specially made for SSDs! Enjoy!
I don't think it works like a charm at this moment.
APFS seems good on some aspect, but the current situation is that perform worse than HFS+.
I've used APFS for about 3 moths, this is what I got
1) Finder unable to correctly calculate and report empty space.
2) Slow boot when TRIM activated
3) Finder micro freeze
4) Bootcamp apps in Windows unable to selected APFS as next boot partition
5) Few APFS related KP (seems fixed in the later High Sierra)
6) No RAID / Fusion support
7) Causing About This Mac -> Storage very slow on getting the space analysis
APFS allow the files breakdown into lots of small fragments. This seems no a big deal for SSD, because the latency is so low on the SSD. However, the OS still need to make more CPU I/O call to read a single file, which does induce more latency, in other words, slower.
The tests so far can't see APFS bring any benefit to the Mac in terms of performance. No matter read / write / boot time / apps loading time... APFS always slower than HFS+ on the same Mac.
The only difference is when "duplicate" file. In this case, APFS's clone ability is far more superior than HFS+.
However, it is also the only benefit that I can enjoy when using APFS. So, unless my workflow require to make / deal with lots of file clones. HFS+ is a far better system for me.
I tried APFS on the first day HS released officially. And after 3 months, I really can't stand for the problematic APFS anymore, went back to HFS+, then be a happy Mac user again.
Of course, YMMV, however, so far, I can't see any real world tests shows APFS really do anything better than HFS+. It's not really specially make for SSD, but can only work better on SSD (compare to HDD). There is a big difference between them!
As I mentioned before, APFS allow fragmentation's, which is extremely bad for HDD, that's why Apple don't recommend anyone run APFS on HDD (but they still allow it). However, let the SSD has full of fragments still a bad idea. It can work, the user may be unable to feel the significant penalty due to fragmentation, but it's definitely not "specially good to make a file system like that for SSD".