Archived Posts from this Category

CPU upgrade

Posted by zdravko on 18 Aug 2012 | Tagged as: Cool, Tech

I have been looking for a CPU upgrade for some time, but since my Mobo is quite old socket AM2+ I was quite limited in what I can get. The best option was AMD Phenom X6 1100T, which is running at stock 3300GHz speed, and also supports Turbo-core at 3700GHz. Going beyond that would have required that all Mobo, CPU and RAM change. So I decided to stay with my current set up and find out that 1100T AMD CPU.

All went well just until I realized that these CPU-s are end-of-life and very hard to find. Not a single one here in Bulgaria, not available in Amazon UK and Amazon DE, and some second hand offers in Amazon US. At that moment I started considering alternatives (as AMD 960T one). I got 965 Black Edition AMD 4-core but still I was looking for 1100T 6-core one. Eventually I found one and bought it for $200 at Amazon.

GPU upgrade is coming…

Micro-Stuttering effect

Posted by zdravko on 14 Jul 2012 | Tagged as: Cool, Tech

Have you got a nice graphical card (and expensive one too) to put it in good use within your computer, which turned out not to be so good for gaming after all (hint, hint Crysis at max settings.) Then you decided to see yourself with a second identical card just to enable SLI / Crossfile and (theoretically) double the GPU performance, and at the end of the day what you see is that the perceived result is not so good as you had expected. And even it is worst compare to single card setup! Why so? Ever heard of phenomenon known as micro-stuttering? Welcome to the club!

Until today it was not so easy to measure the micro-stuttering effect you might see. Just released (as a pre-release) the GPU MIST tool can do that and produce a percentage number (a science bit analysis output) which shows how much your framerate is being affected (read degrade) from micro-stuttering. Download after the jump.

The Scale of the Universe

Posted by zdravko on 16 Apr 2011 | Tagged as: Cool

Zoom from the edge of the universe to the quantum foam of space-time and learn the scale of things along the way! Learn the size of the Pillars of Creation and marvel at the minuscule scale of a neutrino!

Greylisting explained

Posted by zdravko on 27 Oct 2010 | Tagged as: Cool, Tech

Well, I bet you know what a SPAM e-mail message is, so I am not going to explain it to you. I will show you rather how to fight SPAM. One of the most powerful tools against SPAM to chose from is the Greylisting. And it happens that the last day there was a SPAM storm attack against a server running this tool, which is a perfect example how it works in real world. Take a look at the following picture:

Greylisting in Action

I will explain it step by step:

  1. Greylisting will “temporarily reject” any email from a sender it does not recognize (putting it in Pending queue – represented by the blue line).
  2. If the mail is legitimate the originating server will (after a delay) try again, and provided a sufficient time had elapsed, the email will be accepted (moving it from Pending to Verified queue – represented by the green fill).
  3. If the mail is from a SPAM-er, who is being sending many SPAM emails to thousands-or-more recipients, it probably would not be retried, thus time out (timed-out entries are deleted from Pending queue).

In the above example, which is using real data statistics, almost 1000 servers have tried to communicate to that particular server in timeframe of just 4 hours, each of them probably trying to send 100-or-more of SPAM emails. Imagine what amount of SPAM has been filtered out by just implementing a simple Greylisting implementation. Good job, right?

Edit: The issue had auto-resolved in 24 hours (timed-out entries deleted), as it’s visible from the picture below:

Greylisting Resolved

A new project arised!

Posted by zdravko on 07 Jul 2010 | Tagged as: Cool, Tech

Well, you will have to see it by yourself (aha, deja vu) to believe it. Yubiii Preview has been posted at 5Group. Already looking for it?!… (:


2-Factor Yubikey Authentication

Posted by zdravko on 08 Jun 2010 | Tagged as: Cool, Tech

Since I just received my Yubikey from Yubico I was eager using it, so I decided to start with my WP blog. It turned out to be an easy 2-step process once I’ve installed YubiKey WordPress plug-in:

  1. Enabled the plug-in and entered the yubico API key info from here;
  2. Entered my Yubikey OTP in my user’s account settings, and that’s it!

The latest Yubikeys firmware supports 2 configurations – one is preloaded from Yubico. Both can be re-programmed to have two independent and separate configurations, including any two of the three alternatives:

  • Standard YubiKey 44 character pass code;
  • Up to 64 character static pass code;
  • OATH-HOTP 6 or 8 digit code identity.

The result: From now on, I will need to provide my username/password and Yubikey OTP in order to login to my blog. Yubiiiiiiii!…

1337, w00t

Posted by zdravko on 05 Jun 2010 | Tagged as: Cool

Hacker “sp33k” for leet, or elite. Originating from 31337 “eleet”, the UDP port used by Dead Cow Cult, a hacker group, to access Windows 95 using Back Orifice, a notorious hacking program.

Okay, so what /is/ 1337 in the first place? 1337 means Elite. The point of 1337 is to replace all the letters with symbols, and is quite fun to play with. 1337 was first created by some people would wanted to talk in a forum without any outsiders barging in. Some outsiders may have figured out the language and started using it as well. Eventually, 1337 became famous all over the internet. The original use of 1337 is hardly practiced any more, but it survives because many of peope use it for fun.

It takes a long time to translate between regular English and 1337 even if you know all 26 1337 secrets, unless you’re very skilled at it.

Here are the 26 1337 secrets.

A = 4
B = |3
C = (
D = |)
E = 3
F = |=
G = 6
H = |-|
I = |
J = 9
K = |<
L = 1
M = |v|
N = |/| (It is backwards because the frontslash under the backspace key is famous for not showing up on many websites.)
O = 0 (zero)
P = |*
Q = 0,
R = |2
S = 5
T = 7
U = |_|
V = |/
W = |/|/
X = >< (Is normal in words like |-|4×0|2)
Y = `/
Z = 2

S0m3 p30ple 4r3 700 l4zy 70 wri73 7hin65 in fu11 1337, r3su17ing in a 53n73nc3 1ik3 7hi5.

Quotes source:

Overclocking day, again

Posted by zdravko on 28 Feb 2010 | Tagged as: Cool, Tech

Hi there! Again, Overclocking day post. Its has been a while since my last OC day, but I have great news for you:

First, ASUS had released new BIOS versions (for various boards) with improved OC features which refine AMD Core unlocking! Yes, indeed, my AMD Phenom X2 550 processor was recognized as X4 with 4 cores working and unlocked. Pity, Windows always stopped with BSOD no matter what I did. But ASUS did their job well, and in BIOS settings under Unleashed more, you can specify which cores to be unlocked. In my case the faulty core was #3 (starting from zero). So, I was able to boot and load in Windows successfully with 3 working cores: #0, #1 and #2.

Second, I needed a better OC tool to stress the 3 cores. It happened that Orthos is running on 2 cores only, and Prime95 I don’t like since it downloads some data chunks to process, then uploads results. So, a new OC tool was born, and it’s named FFT-z! You can see it in action on the screenshots bellow, next to CPU-z, HWMonitor, FurMark, K10stat and TaskManager applications. FFT-z is not released yet officially, but you can grab a public preview release from here. Expect some new cool features added to it In the next releases.

Cleaning up corporate temporary files

Posted by zdravko on 07 Jan 2010 | Tagged as: Cool, Tech

Imagine your company has hundreds if not thousands of computers. Imagine they are running for at least of a year. How many applications, updates, SP-s were installed meanwhile? How many unused files are left after that? How many temporary files were placed anywhere on those computers? Are your users complaining their computers are getting slow, or that their system drive is full? You want to cleanup! But how?

First of all you download Cleanup Temporary Files (shortly “Cle”) tool. The you setup Logon script for your Active Directory’s users (or OU-s, if you prefer) as this:

REM -- Startup script "user.bat"
REM -- Cleanups the PC temporary and unused files from
REM -- various (hidden) places.
\\SRV-DFS\Files\Audit\cleanup\Cle.exe /custom 32839 /p

then on each user Logon this will happen in the top left corner of the Desktop:

Of course all this could be managed from Cle Configuration application, which brings lots of settings and allows you to cleanup custom specified folders. You can tune up the GUI as well, even you can disable the visuals at all, so Cle would work quietly in the background. Corporate admins could deploy a company-wide Cleanup Policy easily using command-line switches as shows above, and force it to computers using “/s” option.

Noted the magic number parameter after the “/custom”? Well it could be easily obtained from Windows Registry (using regedit.exe) once you have run Cle Configuration. It should be specified as a decimal and not hexadecimal number. Here is its location in the Registry:

Windows Registry Editor Version 5.00
"Selection"=dword:00008047 (32839)

and here is a screenshot of Cle’s Configuration dialog:

OC game day

Posted by zdravko on 17 May 2009 | Tagged as: Cool

I woke up, feeling like some Overclocking should be done today, so I fired my rig’s Power button and started few tools to help me out. The result is my AMD cpu OC from 2700 to 3200 MHz (+18.5%), and my ATI 3870 video card OC from 775/1125 to 837/1215 MHz (+8%). The latest could seems to be not a big deal, but it really helps gaming, I am sure.
Check out the screenshot above. You can click on image to expand it. Now, the Crysis64.exe is calling me…

Edit: Note that CPU OC is using stock voltage of 1.25V. By increasing it to 1.45V you can easily reach 3400 MHz. Quite impressive on air cooling. As for ATI 3870 OC, expect some interesting news next week when I will do ATI 4770 Crossfire testing, so until then.

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