That's normal... HDD vendors use a misleading trick: they measure the HDD capacity in Gigabytes, not in
Gibibytes like PS3 or WIndows do, to magnify the real capacity.
1 Gibibyte = 1024 x 1024 x 1024 bytes = 1,073,741,824
1 Gigabyte = 1000 x 1000 x 1000 bytes = 1,000,000,000
So, a HDD of 500 GB (Gigabytes) is approximately 500,000,000,000 bytes (500 x 1000,000,000 bytes), probably less because they use rounding too.
500 GB = 500 x 1,000,000,000 = 500,000,000,000 / 1,073,741,824 =
465.66 GiB (Gibibytes)
The other missing 55GB (465 - 410) is approximately 12% reserved by Sony for "performance reasons", partitions and other internal stuff.
Check this tutorial if you want to recover up to 8% of that missing space.
https://www.psx-place.com/threads/t...l-space-on-the-ps3-internal-hard-drive.20773/