What's the minimum refresh clock for SDRAM.

Hi All, What's the minimum refresh clock for SDRAM, I knew it depends on ram cell, but could you provide a reference? thank you very much.

How about .25um process / 70ns speed.

Best reagrds, Boki.

in my first PC I had 66MHz PC66 sticks , Bios timings 60ns; I used the largest possible interval = 256us ... no crashes & faster performance ...

as low as possible, because it save power, isn't it ?

Best regards, Boki.

"Tim Wescott" ???????: snipped-for-privacy@web-ster.com...

A longer interval means a less-often refresh cycle, stealing fewer cycles from the processor, albeit I find it a little hard to believe that the difference in performance would be _that_ noticeable. :-)

Cheers! Rich

lower refresh cycle doesn't mean lower processor load.

I can't understand this yet.

Best regards, Boki.

Rich Grise wrote:

ax.com...

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The minimum refresh rate is specified in the data sheet. If you do it less often, you build in intermittent loss of data.

The only way to get reliability at lower refresh rates is to have the vendor select parts to YOUR custom specification.

Quick step up to the soapbox... It's hard enough to make a reliable system if you adhere to all the component specifications. To do otherwise is folly.

A more fruitful question might be, "Which vendors SPECIFY the longest refresh interval?" Soapbox off... mike

Why possible faster?

"Spajky" ¼¶¼g©ó¶l¥ó·s»D: snipped-for-privacy@4ax.com...

because when cells are read & refreshed with refreshing clock impulses, that time are not accessible for write/read operations for other stuff, thus less refreshing, better real life Ram performance; the differences can be up to few % ...

It's not about processor load. You can't read / write memory when it's being refreshed.

Also please don't top post Boki.

Graham

Does it ? Hadn't heard that.

Graham