Hard Drive with 32 mb cache, showing as 23652 KB cache ??

toshiba dt01aca050 hard drive (ebay) not showing full cache, any ideas?? pc spec follows,



HP 6005 SFF PC, Athlon II x4 640, 8GB Ram 4x2gb @1333, hd 5450 1gb, Motherboard HP 3047h 785G (BIOS = HP, 786G6 v01.03). windows 10 pro x64.