Computer Questions Not Worth Their Own Thread II

[Beechlgz]

Do you know where I would be able to get a copy of windows XP and how much for? I've tried amazon, ebay and microsoft. Also tried google, but nowhere seems to be selling it.

 

[Zelig]

Do you know where I would be able to get a copy of windows XP and how much for? I've tried amazon, ebay and microsoft. Also tried google, but nowhere seems to be selling it.

I see lots of copies on ebay going for $50 or so.

I'd really recommend against XP in every potential scenario, Microsoft kills support completely in a year.

 

[Samson]

I see lots of copies on ebay going for $50 or so.

I'd really recommend against XP in every potential scenario, Microsoft kills support completely in a year.

I am no expert, but my choice for a windows virtual box is still XP. Vista is awful, and 7 needs a massive disk, which while it is a lot better in many ways is a bit of an overkill for a little virtual box to open the odd windows only program.

 

[Souron]

My question: Does "top" report the real CPU load, or could the network be maxed out and top still report the CPU load as 100%? I have a process that has 192 cores to do the number crunching and 64 cores to do the database work. Top says the CPU's are maxed out on the database server, so I optimized the query and took the read load off it but the process has not speeded up and the DB is still maxed out. I suspect the network bandwidth, but would have expected this to show up as <100% CPU load. Also, any recommendations for network bandwidth monitoring? [EDIT] This is on Fedora running mysql.

Yeah, network bandwidth should have nothing to do with CPU load.

Database work is generally limited by memory latency. So you want the fastest memory, and a motherboard and CPU that supports that speed. You also want big CPU caches, because databases do try to be cache efficient, but for arbitrary queries, that's not effective. Memory latency issues will manifest as 100% CPU load, so that could be a culprit. I don't know of any tools that would be able to tell you if it is for sure.

Another thing with memory latency, is that having more cores is absolutely no help. 1 core, or 64 cores, on a memory bound application, the performance would at best be the same.

Large databases also read and write stuff to disk, especially if they are low on memory, so you want a fast SSD, but that does not manifest as CPU load.

I'm curious what processor you're using. 64 cores is GPU level.

 

[Samson]

Yeah, network bandwidth should have nothing to do with CPU load.

Database work is generally limited by memory latency. So you want the fastest memory, and a motherboard and CPU that supports that speed. You also want big CPU caches, because databases do try to be cache efficient, but for arbitrary queries, that's not effective. Memory latency issues will manifest as 100% CPU load, so that could be a culprit. I don't know of any tools that would be able to tell you if it is for sure.

Another thing with memory latency, is that having more cores is absolutely no help. 1 core, or 64 cores, on a memory bound application, the performance would at best be the same.

Large databases also read and write stuff to disk, especially if they are low on memory, so you want a fast SSD, but that does not manifest as CPU load.

I'm curious what processor you're using. 64 cores is GPU level.

Thanks for the advice. I am betting on memory latancy. I shall try and track it down by trial and error, by attempting various different types of querys at various load levels and try and work out what it is doing (in about a week, I am on holiday next week).

These are 64 normal cores. We got chassis mounted 16 * 4 core AMD processors for about 5k GBP, each with 512Gb memory. Pretty tasty machines, and I was supprised how cheap they are. My bet is that the intel i7 is so good everyone wants them and the almost as good AMD's are oversupplied. The same computers with i7's would have been 17k GBP.

 

[aimeeandbeatles]

I used this program a whole lot on my old Windows 98 computer. Its still useful, but I'd like to know if anyone knows of a more modern alternative that probably works a little better? Thanks in advance.

 

[aimeeandbeatles]

I used this program a whole lot on my old Windows 98 computer. Its still useful, but I'd like to know if anyone knows of a more modern alternative that probably works a little better? Thanks in advance.

I found this, which does what I was looking for:
http://vvvapp.sourceforge.net/

Edit: (I just noticed how silly that URL looks)

 

[aimeeandbeatles]

I was trying to use regex in Notepad++'s find-and-replace to replace hyphens with spaces while ignoring some other hyphens. Heres what I have so far:

[a-zA-Z0-9][-][a-zA-Z0-9]

But how do I get it to only select the [-] part?

 

[Mise]

google for online regex testers and you can try out the regex in real time

 

[dutchfire]

 

[aimeeandbeatles]

I tried the online thing last night but I cant figure out what to do next

 

[aimeeandbeatles]

I found a regex cheatsheet. That helped.



Would using a &#720; in a filename cause problems later on?
It's this: http://www.fileformat.info/info/unicode/char/2d0/index.htm

I just thought it was a neat workaround to the no-colon rule.

 

[Michkov]

I'd be interested in the cheat sheet, could you post a link?

 

[aimeeandbeatles]

It's available here:
http://www.addedbytes.com/cheat-sheets/

 

[aimeeandbeatles]

Is there a page soemwhere that lists what the entries in Firefox's about:config does? I need to try to figure out how to do something.

 

[Michkov]

Is there a page soemwhere that lists what the entries in Firefox's about:config does? I need to try to figure out how to do something.

Most of them are in here, a couple are missing as addons etc create their own entries and may not be documented.

Thanks for the link btw

 

[aimeeandbeatles]

Okay thanks.

 

[aimeeandbeatles]

Would using a &#720; in a filename cause problems later on?
It's this: http://www.fileformat.info/info/unicode/char/2d0/index.htm

I just thought it was a neat workaround to the no-colon rule.

Well I did it anyways. It can break with programs that dont support Unicode but thats not a big problem.

 

[aimeeandbeatles]

Does anybody else use periods (.) at the beginning of folder names to make them go up to the top of the alphabetical folder list?

(In Windows, you normally cant name a folder with that, but if you add another period to the end it works and deletes the second period -- e.g. .FolderName. becomes .Foldername)

 

[dutchfire]

. signifies hidden in Linux.