Re: Sun Netra T1 amd "memory pickyness"

[Julian Coleman <jdc%coris.org.uk@localhost>]

Hi,
 
> I removed the one module - the second Kinston Infineon - and then it did run
> fine for a day compiling and working (same software, for testing) even with
> less RAM.

So, it looks like some combinations will work together OK.

> Julian Coleman wrote:
> > You didn't mention the part numbers for the RAM that you bought, but it
> > might be that the machine is picky about timing (guessing here).  From a
> > quick look, I see a picture of the 370-4281 (T1 200 RAM) with Infineon
> > part number "HYS72V64300GR-7.5-0" [1] and also a picture of the same part
> > number for Compaq/HP 177628-001 [2].  Maybe you could try that specific
> > Compaq part number or some other with the exact chip?
> 
> part number of the sticks or of the chips?
> They are not original SUN parts, but what I found. should be - per Sun
> datasheet - standard JEDEC Buffered ECC SDRAM.

The part number above is the stick part - the chip part number seems to be
"HYB39S256400T-7.5" in both cases.

> Mixed with bad lucks of a probable bad module, I would say the Kingston
> Infineonn 7.5 is not a nice player.
> It has chips HYB39S256400DT-7.5

And this is strange, as that is similar to the chip that is shown on the
genuine Sun part!  I wonder what the suffix "DT" versus "T" signifies.
 
> Perhaps it makes to buy another DIMM off eBay and see if I have good luck. I
> would say the board is still sound and it is a DIMM issue. Perhaps I can
> read the chips in the picture and stay away from Infineon 7.5 :) Either
> faster infineon or Samsung.

I guess that the machines were tested with some subset of available chips
and the Sun parts have only those chips.  They should all be compatible,
but it seems from your experiments that they aren't.  That was why I thought
that getting a set with the same chips/stick number as a known Sun part would
work.

> Or would trying PC166 RAM make sense? should be retro-compatible.
> 
> Did you also experience such issues with this or similar machines? I did
> check in the manual and all banks are independent, so no DIMM pairing.

I have managed to find Sun parts for my machines.  I did try some HP parts
in the past but couldn't get them to work reliably - now I can't remember
if they had the same chip part numbers as the Sun RAM.  The only machine
where I have succesfully used other RAM is in an Alpha DS20L.  There I have
8 sticks which are all the same (with a Compaq x86 part number).  I didn't
try mixing different chips there though.

Regards,

Julian