How much ram?

dbc254 · 02-03-2006, 06:49 PM

I'm getting conflicting reports on whether more RAM will help or simply be needless spending. I'm currently running Mandriva 2005 (10.2) on a Gateway PIII 933mhz machine with 512mb RAM. It's old SDRAM (PC133) and I was wondering if investing in 1Gb of RAM would speed things up, or just empty my wallet? The machine is fast enough for my needs, but I saw a REALLY cheap price for RAM on eBay, and got curious. Figured I'd ask on IRC and such. VERY conflicting opinions on this. Can someone provide a more definitive answer? Not a gamer, and really only use the box to surf and send emails.

pljvaldez · 02-03-2006, 06:53 PM

In my limited experience, more ram is usually the most economic method of increasing performance on your machine other than rolling your old kernel. Of course, I'm working with an old Celeron 400MHz. For surfing and email, another gig is probably overkill, but as multimedia stuff gets more ram intensive, you may find that it improves your surfing experience.

Just my

stress_junkie · 02-03-2006, 07:03 PM

Make sure that your computer's BIOS can use more RAM. I have a relatively new Compaq Presario that is limited to something like 738 MB, roughly. It would be a total waste to put more RAM into it because the hardware and BIOS cannot access that much memory.

You can probably find out about your machine by going to the manufacturer's web site or by using Google.

WhatsHisName · 02-03-2006, 07:53 PM

Do you need more RAM? Probably not, unless you see significant swap usage.

Should you buy more cheap RAM? Yes. The more the better.

Tinkster · 02-03-2006, 08:02 PM

An off the shelve answer won't cut it... assess what your normal
memory and swap usage is; if you find that your swapper is being
used a lot, more RAM will speed things up. If it isn't, don't
bother sticking more RAM in.

I have 512 MB in my notebook, and certainly don't think I need more,
even with APACHE and PostgreSQL running.

Cheers,
Tink

pixellany · 02-03-2006, 08:39 PM

I would take a different approach---what performance issues are you having? My wife is strictly e-mail and surfing, and can run just fine on 128M of RAM--untill she starts leaving 30-40 windows open. I upgraded her machine from 128 to 192 and it was a HUGE improvement.
If you are not having any issues, save your money.

haertig · 02-03-2006, 09:39 PM

Do some checks on your system with vmstat:

Code:

$ vmstat -a 5 20
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
 r  b   swpd   free  inact active   si   so    bi    bo   in    cs us sy id wa
 2  0    132  17160 475948 384400    0    0    18    17   18   168  1  0 99  0
 0  0    132  17084 475948 384408    0    0     0     3 1251  1032  0  1 99  0
 0  0    132  17076 475948 384408    0    0     0     0 1226   944  0  0 99  0
 0  0    132  17084 475948 384408    0    0     0     1 1250   988  0  1 99  0
 0  0    132  17108 475948 384408    0    0     0     1 1221   958  0  1 99  0
 0  0    132  17092 475948 384408    0    0     0     1 1250  1027  0  1 99  0
 0  0    132  17092 475948 384408    0    0     0     1 1221   946  1  1 99  0
 0  0    132  17092 475948 384408    0    0     0     0 1249   979  0  0 99  0
 0  0    132  17108 475948 384408    0    0     0     2 1222   948  1  1 98  0
 0  0    132  17084 475948 384408    0    0     0     2 1251  1023  0  1 99  0
 0  0    132  17084 475948 384408    0    0     0     1 1221   968  0  1 99  0
 0  0    132  17084 475948 384408    0    0     0     1 1250   965  0  1 99  0
 0  0    132  17108 475948 384408    0    0     0     1 1221   970  0  0 99  0
 0  0    132  17084 475948 384408    0    0     0     0 1250  1008  1  1 99  0
 0  0    132  17084 475948 384408    0    0     0     1 1227   994  0  1 99  0
 0  0    132  17084 475948 384408    0    0     0     1 1251   968  0  1 99  0
 0  0    132  17108 475948 384408    0    0     0     1 1221   948  1  1 99  0
 0  0    132  17084 475948 384408    0    0     0     1 1250   997  1  1 99  0
 0  0    132  17084 475948 384408    0    0     0     1 1220   984  0  1 99  0
 0  0    132  17084 475948 384408    0    0     0     0 1250   985  0  1 99  0
$

Always ignore the first line of output. That's some kind of cumulative average since reboot (meaningless data).

You can see above that of my 1Gb ram, half of that is sitting in the "inactive" state. si and so (swap in, swap out) are zero so there's no swapping going on. Currently I'm the only user on this computer (my home desktop) and it's running Apache, MySql, MythTV backend, X, Gnome, FireFox, and a few terminal windows.

Adding more ram to this system would be a waste. I'm only using about half of what I've got already. This of course is assuming that my current load is the typical load this system sees (with is true).

---

I don't recommend buying the cheapest no-name junk ram you can find. Trying to troubleshoot a problem that is caused by flakey ram can be a nightmare. You don't have to go overboard on cost, but if you find something that's 25% the cost of everything else there's probably a reason for it, and it's not just because all the other manufacturers are ripping you off. OK, I'll agree that $350 for 1Gb of ram, no matter HOW good it is, is a rip off. I don't buy into the super high dollar low-latency ram advocated by gaming enthusiasts. I've been very happy with the medium priced lines from Corsair and Crucial. About $80 a Gb is what I consider "medium priced", and what I'd expect to pay to feel reasonably assured of decent quality. That being said, I have other systems that no doubt came stuffed with the cheapest of the cheap ram from the retailer, and they've worked fine. You pay your money, you take your chances, and somethings you get lucky.

brainiac · 02-03-2006, 10:21 PM

In a study that I read a few years ago 512mb was the point of diminishing return. The five boxes I am running have pretty much proven that. Buying ram at a bargain on E-bay, after I went past 512mb in 3 of them, I really noticed no difference. The only machine to really benefit was my little girls game machine with 1 gig in it. It runs on 98SE and that is a bit much for it to handle. Things happen so fast it leaves a lot of blank radio buttons on the task bar, programs open and close so fast on it I think it is confused. But it will process some intense games with no glitches now. She is slowly taking possession of my Kanotix box so I may end up with hers to switch over and toy with. If enough people throw in their 2 cents you might make it to a dollar.