[H-GEN] A problem...

[Martin Pool]

>On Thu, May 14, 1998 at 01:08:27AM +1000, Robert Brockway wrote:
>> a)  Return the pa2012 and go for an inferior TX based m/b (TX can only
>>     cache 64Mb afaiK). [HX based boards don't support sdram].
>note, here, the TX can only cache the first 64mb, but can support much more.  
>Now, it
>may seem wasteful to have the remaining memory uncached, but given that uncach
>ed
>memory is still a hell of a lot faster than a harddrive swap file, I don't see
> this
>as such a huge problem.  Hopefully most programs will reside in the lower 64mb
>anyway. :)

Except that IIRC Linux will not prefer the lower 64MB of memory: after being 
used for a while, memory will be fairly well mixed and your programs are just 
as likely to be (slowly) executing out of the top of memory.

You'd have to check the source to know for sure, but I imagine that if it has 
potentially useful old buffers in low memory it will start using high memory 
rather than discarding them.

If the machine is massively swap-bound you might still be better off with the 
uncached memory, but otherwise...

--
Martin Pool


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