component speeds slowest to fastest

[michael2002]

i have been taking I.T class and we have this test. we are allowed to to research and get the answers anyway we can . i have a few questions like
what is faster .from slowest to fastest
cd rom , hdd,ssd and ram
as i searched i found people saying things like cd drives are 18000 rpm
so i just had it cd rom slowest from expierience ,hdd ssd and then ram as the fastest method of data transport .and where im not sure is is he talking about data transver rate as ram works in hz and well cd rom and hdd is rpm
thanks

 

[kanewolf]

Comparing those devices, the transfer rates are the key for "fastest". Transfer rate for RAM is the Hz times the interface width (bits) times 2 for DDR.
CDROM has a basic transfer rate -- https://en.wikipedia.org/wiki/CD-ROM#Transfer_rates
HDDs are similar, they have a peak transfer rate in the specs.
SSD may be limited by the SATA bus transfer rates.

Your order is correct IMO.

 

[michael2002]

thank you ,all this is sometimes confusing