The recently released, Ubuntu 13.04, not only brings up-to-date packages (including LibreOffice 4.0), which is pretty usual, but according to its ‘Release Notes’ page, ‘Unity’ desktop 7.0 too brings noticeable improvements, concerning memory consumption & performance.

On a side note, I know this might sound a bit weird, but from all the Ubuntu versions that I’ve tried over the years, the best performing ones (less bugs & solid performance) were the ‘ .04’ numbered versions, the ones that get released in April. Where the ‘.10’ versions are usually buggy.

Anyhow, I decided to write a simple review, by comparing both Ubuntu 12.10 & 13.04, from a performance perspective, including details such as: the Boot-up time, memory usage, initial number of system services, power consumption on idle, CPU usage on idle, ACPI & Hardware issues, system responsiveness, last but not least, the Shutdown delay.

So in this review, I’ll only concentrate on those, rather than writing about software & their new features etc. Here is a simple description about my hardware.

Intel Core i3-2330M CPU, Intel HD 3000 GPU, 4GB RAM (DDR3), Toshiba 7200 RPM (320GB) SATA HDD, Intel N-1030 Wireless adapter, Realtek network adapter ('RTL8168'), LED display with 1366x768 resolution (60Hz/60FPS). It's a Dell Vostro V-131 notebook.

Also remember that, while measuring all the above mentioned tests, I took 5 ‘samples’ of each test, for getting more conservative readings.

Boot-up Time

After clicking the GRUB entry for Ubuntu 13.04 & 12.10, till it booted to the desktop fully, I measured how many seconds it took, compared the results (including the data that I had for ‘openSUSE 12.3 KDE’) & came up with the below graph.

As you can see, there’s is only a marginal difference between Ubuntu 12.10 & 13.04 while booting, but Ubuntu in general, boots pretty fast when compared with ‘openSUSE 12.3’ or ‘Linux Mint 14 Nadia‘.

The main reason behind the fast boot-up of Ubuntu is because of ‘Ureadhead’. It’s a tool (developed by Ubuntu) that reduces the ‘seek time’ & ‘seek distance’ of the HDD (‘ureadahead’ also improves performance on SSDs) while loading the data required for booting, into the RAM.

Reduced ‘seek time & distance’ improves the throughput of the drive & thus leads to faster start-up times. Without ‘ureadahead’, Ubuntu (12.10) takes around 25-27 seconds to boot!.

Memory Usage

Anyway, after that I measured the initial memory usage, upon loading the desktop fully & came up with the below graph.

As you can see, Ubuntu 13.04’s memory usage, when compared to 12.10 roughly shows a 15% decrease!.

Now, it’s very difficult to find what has helped for reducing the memory usage as such. However, I also saw a good decrease of memory consumption of ‘Compiz’, again, upon the desktop log-in.

As you can see, in comparison, ‘Compiz’ in Ubuntu 13.04 has a reduced memory consumption by 22% (roughly), which is also pretty impressive!. You know, I was never that impressed by ‘Compiz’ to be honest, but whoever that did this, I’m sure the users would absolutely appreciate it :).

LightDM has also become lightweight, a lot! …

Another application, in which I saw the most daunting amount of memory reduction was in ‘lightdm’ (display manager) service. I monitored its memory usage upon desktop loading and came up with the below graph.

As you can see, it’s almost a 90% decrease! (89.4% to be precise). However, sometimes, ‘lightdm’ forks another process (with ‘root’ permissions). So just to check, I killed it manually, because if you kill the running processes of your ‘display manager’, one will lose his pretty desktop & the app windows.

But the killing of the ‘fork’ or the ‘non-original’ ‘lightdm’ didn’t do any harm, though its existence is unusual, it’s probably a bug. Now I’m no expert, but perhaps display manager ‘forking’ its own process, with ‘root’ permissions might also lead to some security concerns.

Anyway, there are other changes that have helped. With 13.04, some system services are loaded on demand, rather than running on the background, all the time. Also, some of the ‘Lenses’ that come installed by default, seem to be using a bit less as well.

That said, the ‘Xorg’ process (‘display server’) in Ubuntu 12.10 is around 16MB, but in 13.04, it’s around 31-32MB. But the overall ‘effect’ is a positive one nevertheless.

I also used ‘top’ command in the Terminal to measure how many processes are running. Below is the graph for that (Gnome Terminal’s processes excluded).

Although it seems that Ubuntu 13.04 runs a few more processes, it still manages to cut the memory usage, as mentioned above.

Power Usage at Idle

I also measured the power usage while the computer was idling (Bluetooth OFF, Wi-Fi ON, brightness set to maximum), below are the results.

There’s isn’t a big difference, with Ubuntu 13.04 being slightly efficient, I’ll take that though :).

CPU Usage at Idle

‘openSUSE 12.3’ (closely followed by ‘12.2‘) is one of the best KDE based GNU/Linux distributions, in which I’ve seen impressively lower CPU usage readings at idle. That said, except for the age-long bug (?) in ‘Gnome System Monitor’ which causes 4-6 CPU cycles per-seconds (on my Core i3) when idle, I found that the rest of the processes left the CPU alone, for longer periods.

‘Compiz’ too behaved pretty excellently, as in 12.10, it usually consumes 2-4 CPU cycles somewhat frequently.

Window Handling in ‘Compiz’ (‘FPS’ Benchmarks)

‘Compiz’ is in control of ‘drawing’ application windows, moving them around, adding ‘window control buttons’ etc (although most of the work is done by the ‘display server’ & GTK or Qt interface libraries).

Just like in videos, when an OS is running, the screen that it relies on for displaying its graphical output also has a ‘FPS’ (frames per second), or ‘frame rate’. When nothing is changing on your screen (meaning that it stays as it is, like a still image), the ‘FPS’ should be set around zero, as shown below.

But if a notification comes in, or if the user started to play a video, minimize a window etc, then the ‘FPS’ on the display screen goes up, more or less, depending on changes on the screen. More ‘FPS’ means more work for the ‘GPU’ (video card) & it obviously leads to more power consumption.

Now one thing that I’ve noticed with ‘Compiz’ in Ubuntu 12.10 was that, whenever I opened ‘HUD’, even if I didn’t enter anything to its search-box, and just let the screen to idle, then ‘Compiz’ still renders the screen around a frame rate of 22-23, rather than setting the ‘FPS’ close to zero.

So I though, perhaps it has something to do with the transparency, so to test, I clicked on the ‘Dash’ icon, and kept it opened without typing or anything. Because, if it’s a result of the transparent window (highly unlikely), then the same thing should happen after opening ‘Dash’ as well.

That time however, the ‘FPS’ decreased to ‘0.49’, which is pretty close to zero, and it is more than acceptable. So I hoped that the above issue (under ‘HUD’), would be fixed in 13.04.

I ran the same tests in Ubuntu 13.04 and learned that things are actually gotten worse.

I don’t know whether if it’s an issues with the GPU driver, ‘Compiz’ itself or a bug with the ‘Compiz Benchmark’ plugin (it’s known to come with those). Nevertheless, below is a screenshot of the frame rate, while keeping the ‘HUD’ just opened in Ubuntu 13.04.

As one can easily see, things seems to have gotten pretty bad, as ‘Compiz’ is now showing a frame rate of 59.67, almost 60 — the full ‘FPS’ supported by my display device (the default ‘FPS’ ‘ is automatically detected by ‘Compiz’ based on your display device).

Below is the frame rate that I captured while keeping the ‘Dash’ opened.

Here too, the idle ‘FPS’ has gone from ‘0.49’ to ‘16.03’. Again, I don’t know what is the real reason behind it, but it doesn’t look that good.

ACPI & Hardware Issues

All the versions of Ubuntu that I’ve used in my Dell Vostro V-131 have detected & configured the hardware without any major issues. However, the fingerprint reader has never worked, & sometimes, upon rebooting, the Bluetooth adapter gets turned ON & the brightness also resets to full.

This is also the case with Ubuntu 13.04, but luckily, latter two issues are somewhat easily solvable. While resuming from sleep (in 13.04), sometimes both Bluetooth & the screen brightness got reset, this is the first time it has happened. Other than that, I didn’t encounter any major issues.

System Responsiveness

As usual, I also tested the system responsiveness under heavy multitasking.

While a 1.7 GB size file was being copied (within ‘Home’), I opened Firefox, LibreOffice Writer & Calc, Software Center, System Settings window, Text editor, System monitor, Ubuntu One, opened Terminal emulator for running a command, searched in ‘Dash’, opened & started to use ‘HUD’.

So how did it go ?

It went pretty decently, however, the responsiveness was not as good as how it was under Ubuntu 12.10. Because for few seconds the file copy seemed stuck (‘Compiz’ darkens the so called ‘non responding apps), including few others and the mouse movement wasn’t also as good as under 12.10.

However, given the workload I put 13.04 through, the responsiveness was pretty decent. It was certainly better that how it was under ‘openSUSE 12.3 KDE’.

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Note: Now, I’m not so sure about this, so I’m just gonna say it. I also felt a somewhat aggressive memory management in 13.04. The reason I say that is, even when doing all the above, the overall memory usage had a tendency of quickly changing (reducing), when compared to other versions.

I don’t know with the latest Kernel that comes with 13.04 that they’ve tweaked the memory manager or Ubuntu has written an optimizer by themselves, as I recall a similar incident with ‘Fedora Core 5’. If it’s so, then that could be the reasons behind the slight lag in performance (?)

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Shutdown delay 

I’ve had few issues with the shutdown speed under Ubuntu 12.10. Even when it was working without issues, it still took around 9 seconds for shutting down. It was a bit disappointing when comparing with the 5-6 seconds delay Ubuntu 12.04 had.

But as you can see, Ubuntu 13.04 is one of the most fastest to shutdown that I’ve used so far, as on average, it only takes around 3.7 seconds!.

However, here & there, while both shutting-down and rebooting, the OS got completed stuck. The only fix that could be used, was to use the power button manually. That said, when its working properly, what can I say, it was pretty impressive.

Final words

Despite few issues, Ubuntu 13.04 has managed to decrease the memory usage dramatically, comes with an improved ‘Unity’ desktop & ‘Compiz’ (though it has worsened the ‘FPS’ issue), boots fast (no visible improvements though) & shuts-down impressively faster.

It also includes some nice other changes that I didn’t mention here as well.

So, as a final word, in most aspects, it’s certainly better than 12.10, according to my experience. If interested, you can download it from here, after all, it only costs $70 (just kidding! :D).