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Does upgrading RAM on an old 770 make sense? (Cacheable area

Posted: Fri Sep 19, 2008 9:35 am
by JeriC
So, me again.
Well, I have a ThinkPad 770. When I got it it was equipped with 64 megs of RAM and it came with xp installed (!). I even disassembled an old PowerBook and took the RAM from it to upgrade the RAM in the ThinkPad.
Recently I found some old issues of a German computer magazine (c't, imho the best computer magazine availible here) where there was a test of upper class notebooks. The ThinkPad770 was also tested (and - as the only devide - it was graded ++ in all categories :D ). Well, another tested device came with enormous 128 megs of ram (which was extremely much in 1997), but that was - according to the test - contraproductive.
They wrote something like
"When we reduced the memory to 64 megs, the performance even got better. You might think 'why that', but it's easy to explain:
The TX-Chipset in the $NOTEBOOK can access up to 256 megs of RAM, but its Cache is only large enough for 64 Megs. So if more Memory than cacheable is installed, the performance goes down".
Well, according to the table with the specs, the ThinkPad also has the tx-chipset (and I wonder if it is true that the chipset can access up to 256 megs as I have read that some people managed to install up to 512 megs) and if it is contraproductive to install more than 64 Megs of RAM. If it is so, then it won't make much sense to use (as I currently do) Windows 2000 on it (even if I dont think it is extremely slow). So how the influence of this issue? Is it negligible? When I see the benchmark values mentioned in the magazine (I dont know them any more, but it was something like 'with 128 megs the benchmark had around 20 - 40 % less points') I really ask myself if I should remove memory to have not more than 64 megs installed.

(sorry for my unintelligible way of expressing. I won't even know how to express this clearly in German ;) )Doe

Posted: Thu Sep 25, 2008 6:06 am
by phr
I think there is no such thing as too much ram. If I remember right, I had 256mb in my 770 for a while.

Posted: Thu Sep 25, 2008 6:53 am
by aaa
Not having enough memory and having excess paged to the hard drive is far slower than reduced cpu performance.

Here's an article:
http://www.pcguide.com/ref/mbsys/cache/ ... bility.htm


It's up to you I guess, if you can fit all you need into 64mb without paging to disk too often, then it is better.

Posted: Thu Sep 25, 2008 9:50 am
by JeriC
Ah, I see. Then having less or exactly 64 MB RAM might make sense with Windows NT or something like that, where 64 MB is more than enough, but not with more memory-intensive operating systems.
I did not think about this, but yeah, this makes sense.

Thanks!