Hash count vs Speed
#1
Question 
Noob question that I couldn't find a answer to:

Does the number of hashes being checked impact the speed of recovery?

Examples/environment:

2x5890 (Cypress)
NTLM
HashCat-Plus
plain/BF
avg speed ~8000M/s

~Say around 1000 hashes.

Now, if there was one hash I *really* wanted out of the 1000, would there be any advantage in just hitting that one alone. Or may I might as well hit the 1000 at once. I.E. does pw/s have any bearing on the hash count.
What about 10,000 hashes? At some point would performance not tail off as all the hashes have to be checked? Or are they all in RAM and this isn't an issue.

Sorry if this has (no doubt) been discussed previously.

-=zdz=-
#2
yeah, more hashes means slower speed. that is not because of the hashing, but because of the searching after the hashing if the candidate digest is in the list of wanted hashes
#3
As I suspected.

Many thanks Atom.