September 2016

# How to Boost Your RAM to Declared 3000 MHz?

Sep 2016

I recently upgraded some components of my desktop PC. I was suprised to discover that RAM doesn't work with declared speed of 3000 MHz. Here is the solution I've found to this problem.

Back in the days of DOS I can remember having to set up everything manually, like selecting IRQ number and DMA channel to make sound working in games. But today, in the era of Plug&Play, assembling a computer is easy and everything works automatically. Almost everything...

Although I found that both my new motherboard (Gigabyte GA-Z170-HD3P) and RAM modules (Corsair Vengeance LPX DDR4, 32GB(2x16GB), 3000MHz, CL15 (CMK32GX4M2B3000C15)) support 3000 MHz frequency, it worked on 2133 MHz. Motherboard specification says: "Support for DDR4 3466(O.C.) /3400(O.C.) /3333(O.C.) /3300(O.C.) /3200(O.C.) /3000(O.C.) /2800(O.C.) /2666(O.C.) /2400(O.C.) /2133 MHz memory modules", while specification of the memory has "3000MHz" even in its title. What happened? Motherboard spec calling all the frequencies higher than 2133 "OC" (like in "overclocking") gave me some clue that it is not standard.

After few minutes of searching on Google, I've learn about a thing called XMP (Extreme Memory Profile). It's an extension to SPD (Serial Presence Detect) - a protocol used by RAM modules to report to the motherboard what parameters do they support. I then checked in the specs that my motherboard, as well as my memory support XMP 2.0.

So what I finally did was:

  1. I restarted my PC.
  2. I entered BIOS/UEFI during boot with [Del] key.
  3. I located a setting related to XMP. It is called "Extreme Memory Profile(X.M.P.)".
  4. I changed it from "Disabled" to "Profile1" - the only other option available.
  5. I exited BIOS with saving changes.

That's all! Fortunately I didn't need to manually set any frequency, timings or voltage of my Skylake processor, memory or any other components, like overclockers do. With all the other settings left to default "Auto", the computer still works stable and RAM now runs with 3000 MHz frequency.

By the way: Please don't be worried when you see only half of this frequency in HWiNFO64 tool as "Memory - Current Memory Clock". All in all we are talking about DDR here, which means "Double Data Rate", so the real frequency is just that, but data is transferred on both rising and falling edge of the clock signal.

Warning! It turned out that enabling XMP on my machine makes it working very unstable. Firefox, The Witcher 3 and basically all memory-intensive applications crashed randomly. So if you experience similar issues, you better disable XMP or, if you know any better solution, please post a comment about it.

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# Internet in Poland - My History

Sep 2016

This article at says that yesterday there was a 26-th anniversary of first Internet connection in Poland. On 26 September 1990 scientists made a first connection between Warsaw and Geneva to transfer some data. I thought it might be a good opportunity to write down some memories of my personal beginnings with the Internet. I think it can be interesting to some younger readers that know only the modern Internet as it looks today, as well as to some foreigners, because history of the Internet it other countries may be a little bit different than in Poland.

I know there were things before, like people dialing specific numbers and connecting to so called BBS-es, but my first experiences were already dealing with "this" global Internet. I was in high school back then. At first I started to go to Internet cafes - venues throughout the city where you paid per hours you could spend working on a computer connected to the global network, and possibly downloading some files to your floppy disks. Going there after (or instead of :) school, I first learned how to use IRC and of course WWW. IRC was a protocol that required a client app (mIRC was the most popular one for Windows) and allowed to chat with people, privately or on numerous topic channels, so it was possible e.g. to meet local girls in my city :)

Of course the Web existed already too, with many pages about programming that I've been reading to learn Delphi and download some new components for it. There was no all-knowing Google then, not to mention StackOverflow. Instead there were multiple competing search engines (e.g. Yahoo, AltaVista, Infoseek, Lycos, HotBot) and their algorithms were not so good yet. Page directories were also popular, with manually managed lists of websites grouped into categories and subcategories. Many people created websites about the topics of their interest, like "John's website about programming", or about fishing, or whatever. Pages looked different than today. Their style was to be later called "Web 1.0", with the use of HTML frames, textured backgrounds and animated GIF-s.

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# Pitfalls of Floating-Point Numbers - Slides

Sep 2016

Just as I announced in my previous blog post, today I gave a lecture on a "Kariera IT" event - organized by CareerCon, dedicated to IT jobs.

Here you can find slides from my presentation, in Polish. It's called "Pu³apki liczb zmiennoprzecinkowych" ("Pitfalls of floating-point numbers").

Here are links to the Floating-Point Formats Cheatsheet (in English) that I mentioned in my presentation:

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