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AtW
6th November 2006, 13:14
Bloody risen by at least 25% since start of the year - I have just dropped £650 on memory modules for SKA servers, the price per GB should have DROPPED, not increased!!! Damned Vista :tantrum:

DimPrawn
6th November 2006, 13:59
Fax your MP that memory prices should be pegged by the government to inflation, and that people must save a cash deposit before they can buy any.

AtW
6th November 2006, 14:14
Done.

Face of the MP (it may look otherwise, but she is a woman) is here: http://www.theyworkforyou.com/mp/gisela_stuart/birmingham,_edgbaston

TheMonkey
6th November 2006, 14:16
It depends where you get hold of the RAM from - some places are working on circa-January '06 pricing. I tend to use crucial.com as they are usually the cheapest sh1t that works properly.

I notice that PC133 is REALLY expensive now (i have about 12 gigs of it in a box somewhere!). Woot

Cowboy Bob
6th November 2006, 14:55
I second the Crucial recommendation. That's where I get all mine from. Made the mistake of going elsewhere once. And it was only once. It failed MemTest at its upper limit causing the PC to lock up just before it went into swap.

The Crucial stuff seems to be rock solid.

AtW
6th November 2006, 16:00
Bought 8x1 GB PC 3200 DIMMs Crucial branded... from dabs.com, about 10 quid cheaper than I would have gotten them from Crucial itself - they sure do good memory, they are Micron daughter company or something.

PerlOfWisdom
6th November 2006, 16:03
I can't see why anyone would want any more than 640k. Ever heard of code optimisation?

AtW
6th November 2006, 16:10
I know you are trying to be funny, but what you should consider is that when you deals with objects number of which exceeds billions, or even trillions in some cases it means that if you don't keep them in memory you will have at least a fixed cost of a disk seek - that applies to cases when you can't access data sequentially of course - this means that performance becomes seriosly limited by disk: even if you talk about sequential access it is still good 2 orders of magnitude slower than accessing same data in RAM.

PerlOfWisdom
6th November 2006, 16:18
You should have seen my 36-ary in-memory tree structure for looking up words and phrases. Did about 500,000 lookups per second on a bog standard PC. In Java!

AtW
6th November 2006, 16:20
How many unique words, and how long (bytes) on average they were?

PerlOfWisdom
6th November 2006, 16:24
About 70,000 - the unix words file. Used about 1K per word.

AtW
6th November 2006, 16:29
About 70,000 - the unix words file. Used about 1K per word.

Ok old chap, I won't be disrespectful to your achievement because I am wiser now, but read the following thread very carefully: technical challenge (http://forums.contractoruk.com/thread11616.html)

I don't want to spoil it for you, but here is the most important last message that I posted there:



Ok, a bit disappointing not to see any estimates, but I had pretty low expectations in the first place.

Anyway, here are the results of benchmarking (on AMD Athlon x2 3800 - single core used):

0) no caching tricks - search pattern is expected to be evenly distributed
1) 100 mln unique strings of 20 bytes each, data size: 2 GB
2) Indexing takes 30 mins
3) Generated index size is ~810 MB.
4) Running searches for 10,000 randomly selected strings, with 100 runs (total 10 mln searches) results in a sustained performance of ~232,000 (that's thousands) searches per second.

The system supports multiple indices, so it's not like everything is done for 100 mln strings: scalability is perfect because by adding 2nd CPU you will get double the speed, same goes with extra machines which will not offer extra speed but also load balancing and redundancy.

Could you do better than that? I doubt it. Not because I think I am so ****ing amazing, but because low level algorithms used in the system are such that mathematically pretty much perfect: you can't cheat them with probabilistic modelling because searches will be evenly distributed so caching tricks are off.


So old chap, you had 70k words and I had 100 mln words - performance is pretty similar, but I had ~1500 (about one thousand five hundred) times more data - algorithm is such that size of word does not matter, could have been 10k bytes each.

Now you do understand that when I buy more RAM I know exactly what I am doing?

TheMonkey
6th November 2006, 16:58
Bought 8x1 GB PC 3200 DIMMs Crucial branded... from dabs.com, about 10 quid cheaper than I would have gotten them from Crucial itself - they sure do good memory, they are Micron daughter company or something.

Yeah but buying dabs is always a risk. Crucial from Crucial ALWAYS arrives the next morning, even if you order it at 6pm the day before!

MrsGoof
6th November 2006, 17:04
Yeah but buying dabs is always a risk. Crucial from Crucial ALWAYS arrives the next morning, even if you order it at 6pm the day before!
Amazon can be just as bad. Order something at 7pm for 2 to 5 day free delivery. Then at 8am the next day some bloody courier is banging on the door with the delivery. Selfish buggers!

AtW
6th November 2006, 17:04
I buy stuff from dabs.com about once a month, I think twice products were faulty and they replaced it all quickly enough for me. They ship next day even though I don't pay extra for it. Prices for disks are very keen too, and in this case crucial RAM was 10 quid cheaper.

Forumbore
6th November 2006, 17:15
The price of memory these days eh? Its those alzheimer sufferers I feel sorry for

AtW
6th November 2006, 17:22
I remember time when 1 MB cost £40.

TheMonkey
6th November 2006, 17:25
I remember time when 1 MB cost £40.

That's pathetic. I remember when 64k EPROMs cost that much, and I'm not THAT old as techies go...

AtW
6th November 2006, 17:29
I remember when getting 1 concrete block to the pyramids cost 40 slaves.

threaded.

TheMonkey
6th November 2006, 19:21
:rollin:

Joe Black
6th November 2006, 20:47
That's pathetic. I remember when 64k EPROMs cost that much, and I'm not THAT old as techies go...64K for £40, you don't know how good you had it.

In my day we were lucky to share 16K between 8 people and it cost as much as a new car!!!

Joe in "not far from the truth" mode.

TheMonkey
6th November 2006, 21:15
64K for £40, you don't know how good you had it.

In my day we were lucky to share 16K between 8 people and it cost as much as a new car!!!

Joe in "not far from the truth" mode.

Yeah and the bloody valves kept going...

hattra
6th November 2006, 21:55
That's pathetic. I remember when 64k EPROMs cost that much, and I'm not THAT old as techies go...

Right,

I remember when the 4k upgrade for our PDP-8e cost £1000, and you wouldn't believe how much we spent on paper tape and ribbons for the teletypes ...........

Not that I'm that old, really

AtW
6th November 2006, 22:19
I remember when the 4k upgrade for our PDP-8e cost £1000

How much was average house price back in those ages?

hattra
6th November 2006, 22:31
How much was average house price back in those ages?

I was only 14...

and we didn't live in an average house :p

Seriously - that was about 1969 - probably around £4 - 5000 for a three-bedroomed semi - my parent's house in England was £8000 (rural Bedfordshire) - obviously London prices were higher, like now.

PerlOfWisdom
7th November 2006, 09:25
How much was average house price back in those ages?
Only fools bought houses in them days - the insane inflation of house prices couldn't continue.

AtW
7th November 2006, 12:04
Only fools bought houses in them days - the insane inflation of house prices couldn't continue.

Oh, so no comments about my implementation of the code that was searching for 1500 times more data than yours? I thought so! :o

DimPrawn
7th November 2006, 12:13
Oh, so no comments about my implementation of the code that was searching for 1500 times more data than yours? I thought so! :o

There is no doubt AtW that you are the best person in the world at writing C# code for searching for data in the format you have created that is specific to what you are doing at the moment.

I am the best person in the world at writing in my own handwriting.

AtW
7th November 2006, 12:20
Running url loading process on 6 CPUs that deduplicates urls found on 5 bln crawled pages - approximately 50 bln urls (long strings) in question I think, once they are deduped against each other I will need to dedup them against existing 22 bln unique ones I have.

And this kind of stuff is child's game for me now - I work on far more advanced concepts that in a couple of centuries will approach the complexity of the stuff threaded has been working on in the middle ages :wave:

DaveB
7th November 2006, 12:27
Back in the late eighties I dabbled in the 2nd had server and components market. Picked up a Dell box that was supposed to be pretty basic. Opened it up to check everything was in order and found 2x512mb SIMMS that I wasnt expecting. Prices on the 2nd hand market back then were around £350 quid each. Result :banana:

Surplus memory was always a nice little earner from doing upgrades on business sites as well. 20 pcs going from 64mb to 128mb meant a nice stack of 16 and 32mb SIMMS to be "disposed of" :D

PerlOfWisdom
7th November 2006, 12:52
I know you are trying to be funny, but what you should consider is that when you deals with objects number of which exceeds billions, or even trillions in some cases it means that if you don't keep them in memory you will have at least a fixed cost of a disk seek - that applies to cases when you can't access data sequentially of course - this means that performance becomes seriosly limited by disk: even if you talk about sequential access it is still good 2 orders of magnitude slower than accessing same data in RAM.
So what you're saying is that 640k is not enough for some jobs?

PS in all the languages in all the countries in all the world, there aren't 100 million words.

AtW
7th November 2006, 13:02
PS in all the languages in all the countries in all the world, there aren't 100 million words.

Well, how many unique words you think used on the world wide web?

Of course many kindergarden programmers never in their lifes face real tough world-class problems to solve, but someone has to do it. :o

DimPrawn
7th November 2006, 13:04
When you make some money out of this, I'll admire you.

Till then, it's just a pointless hobby.

PerlOfWisdom
7th November 2006, 13:07
Well, how many unique words you think used on the world wide web?

Of course many kindergarden programmers never in their lifes face real tough world-class problems to solve, but someone has to do it. :o
Depends how you define a "word"



Anyway, I thought you weren't going to disrespect my achievement:-


Ok old chap, I won't be disrespectful to your achievement because I am wiser now,

Edit:
I wish all my "real tough world-class problems" just involved sitting in a warm room clicking a mouse and pressing keys.

AtW
7th November 2006, 13:09
When you make some money out of this, I'll admire you.

This is what I want to do - it also brings money, so far I have broken even and well on track to exceed my permie wage, in fact I have done so since I can get hardware more tax efficiently than otherwise. More importantly I am becoming a consideraly better programmer, could not care less if I am the best or not, but I want to know that I improve.

Perl - I am not disrespecting your achievement, I am just trying to make it clear that there IS use for more memory: my 8 GB of RAM have just arrived :o

Joe Black
7th November 2006, 18:47
Right,

I remember when the 4k upgrade for our PDP-8e cost £1000, and you wouldn't believe how much we spent on paper tape and ribbons for the teletypes ...........

Not that I'm that old, reallySeems you were much more ahead of the game than me hattra. Where I was we were spoilt with one of those new fandangled PDP-11s.

Ah, those were the days, reading the boot code off a torn in half line-print while you flicked the final 16 switches and hit the execute button. :cool3:

hattra
7th November 2006, 21:29
I'd forgotten about the load sequence - IIRC you had to load the first 16 or 32 bytes through the front panel, which told it how to load the bootstrap loader (a few hundred bytes on paper tape), which then told it how to load the O/S (also on paper tape). Oh the joy when we finally got an optical paper tape reader and could load the O/S in 2-3 minutes, rather that the 45 minutes it took using the tape reader on a teletype (and which we usually had to do twice a day).

I think I've still got a listing for "Moonlander" that we wrote in Focal

TheMonkey
7th November 2006, 22:09
Thinking about it, I had something slightly worse a few years ago. I had a desktop calculator (the manufacturer escapes me) which had nixie tubes and no ICs - everything was about 3000-odd transistors inside it on 15 cards.

It didn't work though. Made a nasty burning transformer smell and blew the fuse after about 20 seconds. I would have repaired it if I could have found the schematics.

hattra
7th November 2006, 22:25
A teacher at my school built his own computer, out of reed switches (it was his PhD project). The only computer I've ever heard that rustled as it worked

DimPrawn
8th November 2006, 09:10
I remember when each 64TB RAM module for the Intel Million Core processor cost over 4000 Galactic Credits.

Threaded.

PerlOfWisdom
8th November 2006, 10:57
I remember when each 64TB RAM module for the Intel Million Core processor cost over 4000 Galactic Credits.

Threaded.
Are they the triangular rubber coins six thousand eight hundred miles along each side?

DaveB
8th November 2006, 11:00
Are they the triangular rubber coins six thousand eight hundred miles along each side?


No, thats the Ningi.