Upgrading an 030/25 mhz accelerator

[Miked]

If you increase the speed of a 030 accelerator, do you need to use faster memory?  For example, if you are using a derringer 030/25 which is using a certain speed SIMM (e.g. 80ns); if I were to modify the card by replacing the oscillator and adding a 50 mhz 030, do I need to change the SIMM memory to 60 or even 50ns Ram?

-Miked

[Miked]

Well, there was a Derringer that ran at 50mhz.  But aside from that, my real concern is the ram speed.  Did these accelerators take fpm memory or edo memory, parity or nonparity?  Or does it not matter?  

Additionally, searches for 40ns/50ns 32MB 72pin SIMMS have been unsuccessful.  Can it run at 50mhz with 60ns Ram?

Anyone have a 50mhz Derringer?

-Miked

[Miked]

Ilwrath wrote:

In other words, running a 2x multiplier 25mhz clock for the 50mhz version vs. a normal 1x multiplier 25mhz clock on the 25mhz model.

Interesting.  So, the speed of the ram really isn't that much of a concern?  Assuming it did work (doubling the clock speed) what would be the implications of using the same speed ram that ran in the 25mhz version?

-Miked

[Miked]

HyAmi wrote:
Derringers for sale at the time; 25 and 50MHz. I asked this person if there were any differences beside the oscillator. He compared he cards and answered that there were some parts different (can't remember which) but the 50MHz version did have better (read: made for higher clock frequencies) parts.

In the end, I didn't try it at all. The risk of frying a card like this... Maybe a little overclocking. But if I'm just too carefull, please tell me what's possible!

Hmm, I wonder if there is a current-voltage difference between the 2 cards.  (Id be curious to know if any resistors are different).

I just spoke to someone who has clocked his 25mhz derringer at 33mhz.  He simply put in a 66mhz oscillator in the card and changed the 25mhz 030 to a 33mhz one.  So, at the very least, an 8mhz gain can be had.  (whats the speed increase? 24%?)

I still say its worth a try to drop in a 030/50 and get a 100mhz crystal and some 50ns (or faster) ram and see what happens.  

-Miked

/Edit
 I suppose since there is electrical oscillation that the capacitors might be different as well (25mhz vs 50mhz card).