(48GX) SpeedUI 14.01 released:-)

[Christoph Giesselink]

(08-14-2016 07:54 AM)JDW Wrote:  By the way, I spoke to a seller of FRAM cards on EBAY. I asked him about speed. He said FRAM cards care much faster than SRAM cards (which need a battery), but that the 48GX will limit FRAM card speed. Even so, he said FRAM cards will be 20-30% faster than SRAM cards in the GX.

I don't know why the seller talk about FRAM is much faster. Much faster than what?

I agree FRAM is much faster than any Flash or EEprom chip, but not comparing to SRAM.

Let's have a look, a normal SRAM 128Kx8 chip is available with access times of 70ns, 55ns, 45ns and 35ns. Decades ago, such a SRAM chip had access times of 70ns or 100ns.

Actual Cypress FRAM chips 128Kx8 as replacement for SRAM chip have a random access time of tRC = 90ns (Cypress FM28V100 Data Sheet) for the 3.3V type. I haven't found a 5V type so I don't how they could be a replacement for a 5V SRAM?

So comparing the random access times between SRAM and FRAM they are mostly identical.

The Saturn CPU core is slow down by many factors. First by the memory interface translating the 8bit parallel access to the multiplexed 4 bit Saturn bus protocol and finally by the Unified Memory Architecture sharing the RAM memory between CPU and Display driver.

So I wouldn't expect any noticeable speed difference.