Quite a number of people are aware of the PAE which can extend the addressable space from 32bit up to 36-48-52bit (depending on the implementation; as I understand, Windows PAE extends to 36 bits, or 64GB of addressable space). However, overwhelming numbers of internet pages continue insisting that a not-more-than-4GB limit for the 32bit Windows is the consequence of 2^32 = 4GB architectural limit.

There is an excellent, in-depth, well-argumented article by Geoff Chappell on the issue. Highly recommended in its entirety to those who want a complete understanding (additional side-reading and facts verification might be necessary).

A single citation to get you started:

There is already on the Internet and elsewhere an awful lot of rubbish to read about this question. Hardly any of it would be worth citing even if I didn’t want to spare the authors the embarrassment. A surprising number of people who claim some sort of attention as expert commentators would have you believe that using more than 4GB of memory is mathematically impossible for any 32-bit operating system because 2 to the power of 32 is 4G and a 32-bit register can’t form an address above 4GB. If nothing else, these experts don’t know enough history: 2 to the 16 is only 64K and yet the wealth of Microsoft is founded on a 16-bit operating system that from its very first version was designed to use 640KB of RAM plus other memory in a physical address space of 1MB. Some remember this history and add seemingly plausible qualifications that exceeding 4GB is possible only at the price of nasty hacks that require everyone—well, all programmers—to jump through hoops. Fortunately, Intel’s processors are a lot more advanced than the 8086 from all those years ago.

P.S. Unfortunately, patching the kernel won’t help make Windows XP see more than 4GB RAM: even though the kernel itself does support more RAM (with PAE), starting with SP2 the HAL was modified in a way prohibiting access to any RAM beyond 4GB. Patching may only be suggested to devoted geeks with Vista’s and 7′s.

Will be useful to anyone dealing with more than 1 piece of computer hardware: Disk failures in the real world: What does an MTTF of 1,000,000 hours mean to you?

To get the essence quickly – just scan the tables and figures, and read conclusions.

You might want to read what google engineers tell about HDD failures.

I assume you already have configured and working desktop environment, but want to improve performance.

First of all, sudo aptitude install mesa-utils. Then run in a Terminal/Konsole glxgears, and wait for ~15 seconds; if your FPS is ~400 or less, then you do have sluggish video performance (usually manifesting itself as slow scrolling in Firefox/Iceweasel, slow window switching/minimziing/maximizing etc).

After reading through several forums and bug reports and blog posts, I’ve ended with the following modifications to my /etc/X11/xorg.conf:
Read the rest of this entry »

Personal communication resulted in a link to slicehost, who provide VDS/VPS services at prices as low as 20$/mo, which is comparable in price to good shared hosting plans, and is cheaper than Dedicated plans.

I’m considering a move from shared hosting, and found Slicehost attractive. For 20$/mo, you get guaranteed 256MiB RAM, 10GiB disk and 100GiB traffic, which is sufficient to host several under-1k-per-day sites.

The only thing which isn’t spoken aloud is the guaranteed CPU speed. Based on the numbers provided: 16GiB total RAM per server, quad-core CPU, and CPU quotas set equivalently to RAM quotas, I came to a conclusion that 20$-plan guarantees ~125MHz of CPU (take 16 GiB, multiply by 4 20$-plans – you get 64 “slices” – virtual servers; quad core CPUs were quoted as 8+GHz – I assume that’s the sum of the core frequencies, thus 8GHz divided by 64 slices gives as little as 125MHz guaranteed per slice).

The better slice you buy – the more CPU is guaranteed, so for 1024-RAM slice you’d have a minimum of 500MHz of CPU.

However, slicehost describes their CPU-clamping system as the one allowing “bursted” performance, if others aren’t actively using their CPU shares. So it must be much better than what I’m calculating here. And even if it’s not, then for some applications it’s better to have a 125MHz-clamp on CPU, than have a 20-seconds maximal CPU time limit.

Still, I’m looking for reasonably-priced collocation services in Ukraine – e.g. those (currently unavailable) from Volia, starting at 40$/mo for the rented physical VIA C7-based server with enough traffic included.

Update: I now have my own server collocated in Ukraine. This blog still lives on a shared hosting, but I’m considering the move to own server (where I have the biomed half-dead site and resource-hungry COTRASIF tool).

A year, maybe two ago, I came across the news that someone’s constructing a “building printer”, in the sense that it is first filled with liquid concrete, and then – given the schematics of the building – “prints” concrete, producing almost-any-complexity architectural forms. Unfortunately, the names and links to that instance of object printing was lost and forgotten.

However, I have just stumbled upon the news item about RepRap, which is claimed to be “self-reproducing”. Clearly, this isn’t true, but RepRap – replicating rapid prototyper – is able to produce (some?) of the components necessary to build another RepRap.

I’d like to point out that

“Think of RepRap as a China on your desktop.”

by Chris DiBona, Open Source Programs Manager, Google Inc., is an offensive and unacceptable phrase, which shouldn’t have been put at the top of the quotes. I’d hack down that RepRap website for this single quotation, and would feel vende vindictive towards Chris, if I were Chinese. But that’s not a long time to wait to see China rising and this kind of jokes vanishing.

That was a side note.

Continuing on RepRap, I do find it’s uses intriguing. For the best of everybody, there’s a how-to build reprap page.

First uses which came to my mind were… a new plastic cup, and a custom notebook/PC body/case, to put standard components into and enjoy the benefits of the perfect custom design

Apart from simple things like cups and actually “fast prototyping” (which does depend on the precision of RepRap), there aren’t that much uses for the SOHO owner of RepRap. But as soon as some small-scale silicon-growing/cutting machines become available, that would definitely open up the whole new world of custom gadgeteering and home-brewed electronic wonders. Also, the level of global and local espionage activities will explode, and Big Brothers will grow like mushrooms after raining cats and dogs.

Failure Trends in a Large Disk Drive Population (or here, if that link doesn’t work)

Worth reading for any IT guy, especially for people dealing with lots of HDDs.
Also might be interesting for those, who have Gmail with (now) over 6GiB storage…

Today, using memtest86, system speed test, hddspeed and some other DOS utilities for diagnosing and testing PC hardware, I decided to put together my own simple bootable utility CD disk. But first, I did some searching to find if something similar exists.

It does exist – Ultimate boot CD. That CD has numerous freeware testing and diagnosing utilities which will help you – if you are up to some good old (read “small fast”) DOS utilities. And not that old, actually – modern hardware is supported.

The only modification I’ll do to the Ultimate boot CD will be adding freeware bin/hex viewer/editor. Surely, more utils to come – with original size of just 115MB, there’s plenty of room to add extensions. You can even extend the CD image with non-free software, like Partition Magic.

P.S. To diagnose and fix software problems – have a look at System Rescue CD.