Does Gigabit degrade all ports to 100 megabit if there is a 100 megabit device attached?

Our company is buying some HP Procurve managed gigabit switches to replace some of our core switches. However, we aren't able to upgrade all of our switches from 100Mb to Gigabit switches. I think I know the answer but I'm not exactly sure. If we plug those 100Mb switches (or even a 100Mb device) into those Gigabit switches, will the performance of the entire switch drop to 100Mb or will just that one port work at 100Mb?

From serverfault hjoelr

• Just that port.

  hjoelr : Great! That's how I thought it worked, but just wanted to make sure.
  From mfinni

• If you can avoid cascading switches, I'd strongly encourage it. The downsides are easily exampled with two people on the same cascaded switch copying a large file to a fileserver. Having a single user under normal usage being able to cause usage issues for multiple other users is obviously bad.

  Implications are even worse with servers.

  hjoelr : Yea, I totally agree with you. We are planning on removing the cascade switches when we get a chance to completely re-wire our 40-year-old building.

  David Spillett : Many Gbit switches have FP ports that would allow you to install ports to link between then, reducing (but by no means removing) the potential performance problems with cascaded switches by providing a faster (10Gbit) backbone for them to talk over. The fiber modules and related kit may be prohibitively expensive for you at the moment, but it might be worth getting switches that support this for future proofing.
  From Warner