[Info-vax] 512MB DIMMS - 4GB in Alphaserver 1200

[gah4]

On Thursday, March 10, 2022 at 12:21:21 AM UTC-8, geze... at rlgsc.com wrote:

(snip)

> A word of caution concerning documentation, and, for that matter testing. 
 
> The documentation may, in effect, be incorrect. The Alphaserver 1200 documentation was likely written before the larger capacity chips were available. Have had this with disk drives and with memory slots. Both ways (some things worked, and some did not). In recent history, my Dell Latitude 6000-class laptop documentation says "maximum 8GB RAM", but it is quite happily running with 16GB. However, my Alphastations do not have the cooling capacity to deal with some of the 3.5" inch disks, I was warned. 
 
In the case of DIMMs, there are/were some that are two sided, which means that
they use two select lines, not necessarily that chips are on both sides.
Some systems needed one kind and not the other.  

Both disks and RAM could use more power and overheat, but also later
models will often use less power, and so that goes away. 

Or some RAM might have more capacitance load than the system was
designed to drive.  But again, that might go away with later models.

> Also, if testing, one should be careful to actually test the expanded memory. Some problems show up as address overmaps, which can cause, to put it politely,challenges. 
> 
> - Bob Gezelter, http://www.rlgsc.com