🚀 go-pugleaf

I am running a Centris 610 with 12 Mbyte RAM, and now is the time to
upgrade as Netscape apparently wants 16Mb in its new(ish) incarnation, and
MacOS 8 requires 8 Mb.

Can anyone definitively tell me if higher speed SIMMs will work/have any
deleterious effect.

The Apple specs say '80ns or faster', MacGurus at www.macgurus.com give
dire warnings about using the wrong speed, then say their 70ns SIMMs work
fine.

60ns SIMMs are ubiquitous and extremely price competitive - so any
problems using them?

Finally, I believe that whatever SIMM is used, it requires a 2kHz refresh
rate - are there any manufactured that aren't?

Finally, finally - does anyone know if the Centris senses SIMM speed (I
think using presence line which have comninations of resistors on the SIMM
to indicate it's speed to the hardware).

And finally finally finally - any experience of using Mac Supplies or
Discs Direct, both of whom seem to have competitive SIMM prices.

Thanks in advance.  I would be grateful if replies are e-mailed to
pgrb(at)ygdrasil.demon.co.uk as I can pick up email via the Web through my
firewall at work - Usenet access is banned.

Regards,

pgrb 

P.S. above questions also apply to VRAM - the Centris 610 specifies 100ns
VRAM, other Macs 80ns.