El 10/03/2021 07:53, "Marco Möller" <talby@debianlists.mobilxpress.net> escribió:
>
>
> On 10.03.21 04:34, Cmdte Alpha Tigre Z wrote:
>>
>> Hello.
>>
>> I would like to install Debian 10 with the KDE Plasma task
>> on a PC with 4 GB of RAM and Intel Core 2 Duo E6550 @ 2.33 GHz,
>> it doesn't have a GPU.
>> Do you think it would run without problems
>> or would it be slow and laggy?
>>
>> Thanks in advance for your answers.
>>
> I am happily using KDE Plasma on such a system as my daily system with the following restrictions:
> (1) The L2 cache of your CPU should have 3 MiB or more; with only 2 MiB it is not always responsive as wished, and with only 1 MiB it is due to low responsiveness in my experience not usable anymore; the number of CPU cores, threads and frequency in my experience are not the key factors for a responsive = smoothly usable system;
> (2) You might want to limit or deactivate the automatic indexing provided by "baloo", configurable also in the System Settings GUI under "Search" in subcategories "File Search" and "KRunner"; right after installation it wants to index all your system, and the system might in this state not be responsive for some 2 days; I therefore deactivate this as soon as possible, get the rest of my system set up and usable, and only later, when I can leave the system run for a weekend without the need to interactively work with it, I reactivate baloo features again, but only the ones for which I indeed know that I want to use them; once the initially very system consuming indexing is done, this baloo provided search "accelerator" does not impact responsiveness anymore; it continues in the background to smoothly update the indexing of newly added content without interfering with the actions called in the foreground by the user;
> (3) I am sorry having to suggest even as an enthusiastic KDE user, that you might want to avoid installing the KDE PIM suite related apps like KMail; although I loved the design of its GUI and work flow a lot, it was not only slowing down the responsiveness of the desktop often, but also crashed too often; this experience is from 5 and from 2.5 years ago; after this bad experiences and Thunderbird meanwhile being very well maintained again, I am not going to give KMail another try and will very satisfied stay with Thunderbird for email, calendar and address book;
>
> I finally 2.5 years ago came from long time back in the past GNOME usage, then Xfce, then Openbox, then LXDE, then LXQt, then LXQt with kwin usage to KDE Plasma and confirm that KDE Plasma is very competitive on memory and speed. I do not see any reason for not using it on old machines, see my system specifications attached below. You will see that I am on KDE Plasma as currently offered in "Debian/testing - bullseye" and do not know about the very newest version 5.21.
>
> Operating System: Debian GNU/Linux
> KDE Plasma Version: 5.20.5
> KDE Frameworks Version: 5.78.0
> Qt Version: 5.15.2
> Kernel Version: 5.10.0-4-amd64
> OS Type: 64-bit
> Processors: 2 × Intel® Core™2 Duo CPU P7450 @ 2.13GHz
> Memory: 2,9 GiB of RAM
> Graphics Processor: Mesa DRI Mobile Intel® GM45 Express Chipset
>
> The CPU and memory consumption of pure KDE Plasma with only the "Konsole" terminal app open for generating the presented data are these:
>
> $ sudo inxi -Cm
> Memory: RAM: total: 2.88 GiB used: 1.2 GiB (41.8%)
> Array-1: capacity: 4 GiB slots: 2 EC: None
> Device-1: M1 size: 2 GiB speed: 667 MT/s
> Device-2: M2 size: 2 GiB speed: 667 MT/s
> CPU: Info: Dual Core model: Intel Core2 Duo P7450 bits: 64 type: MCP L2 cache: 3 MiB
> Speed: 798 MHz min/max: 800/2133 MHz Core speeds (MHz): 1: 798 2: 798
>
> $ free -h
> total used free shared buff/cache available
> Mem: 2.9Gi 779Mi 1.2Gi 282Mi 959Mi 1.7Gi
> Swap: 7.6Gi 71Mi 7.6Gi
>
> You will see that pure KDE Plasma is easily provided at lowest processor speed and with a smaller than 800 MB memory footprint.
>
>
> If running Thunderbird for writing this answer to you, having a messenger app running, having the System Monitor and the terminal app Konsole started in order to check for you my current memory usage, and having Firefox open with 6 Tabs while all Firefox cache for better responsiveness is placed in the RAM and not on the HDD (actually I am running all my system even without a HDD from a USB2.0 pendrive only), you will see that the CPU is busy - but my system is still nicely responsive and doing for me flawlessly what I ask it to do.
> You might have noticed that on my hardware I am only getting access to 3 GiB RAM, although 4 GiB are installed, and I never found out how I could overcome this limitation.
> When "inxi" (see below) reports that almost all this 3 GB of RAM would be in use, then this is because Debian is nicely using all RAM not claimed by my running apps for caching, in my configuration mainly for caching file system information. So, all memory is fully in use, this is how it should be, there is no need to have RAM and then not using it. The systems gives to my apps what they require and is then using the rest for caching mechanisms enhancing for me the system responsiveness and thus user experience. Either the KDE System Monitor, or simply the "free" command (see below) confirm that only 2.2 GiB are in use by me, the free rest is taken advantage of by the nice caching features.
> Here the data at usual load when using my laptop as my office computer:
>
> $ sudo inxi -Cm
> Memory: RAM: total: 2.88 GiB used: 2.71 GiB (94.3%)
> Array-1: capacity: 4 GiB slots: 2 EC: None
> Device-1: M1 size: 2 GiB speed: 667 MT/s
> Device-2: M2 size: 2 GiB speed: 667 MT/s
> CPU: Info: Dual Core model: Intel Core2 Duo P7450 bits: 64 type: MCP L2 cache: 3 MiB
> Speed: 2124 MHz min/max: 800/2133 MHz Core speeds (MHz): 1: 2124 2: 2113
>
> $ free -h
> total used free shared buff/cache available
> Mem: 2.9Gi 2.2Gi 66Mi 436Mi 625Mi 103Mi
> Swap: 7.6Gi 18Mi 7.6Gi
>
> I know that half of the "used" RAM usage is caused by Firefox, its opened tabs, and me having configured all Firefox cache temporarily being moved into the RAM.
>
>
> In another output I show you the memory consumption with only Thunderbird being opened while all other apps have been closed, and having applied the "sync" command before gathering the data:
>
> $ free -h
> total used free shared buff/cache available
> Mem: 2.9Gi 1.1Gi 1.1Gi 277Mi 707Mi 1.4Gi
> Swap: 7.6Gi 74Mi 7.6Gi
>
>
> To summarize my years long experience being bound to very old hardware:
> The most critical parameter is to have the L2 cache of your specific CPU to equal as the absolute minimum at least 2 MiB and then accept in any graphical desktop environment some lag in responsiveness, or to highly preferred have at least 3 MiB or more L2 cache available and then being able to get usual office work done at acceptable performance.
> It then are the running apps which let you face performance limits, but not the KDE Plasma (or LXQt or LXDE or Xfce). Concerning this, you will nowadays need at least 3 GiB of RAM, and if your motherboard supports it you want 8 GiB of RAM or more.
>
> Your Intel Core 2 Duo E6550 comes with 4 MiB of L2 cache, and with the already present 4 GB of RAM you can use it for KDE, and then for running in parallel some (few) usual office apps. If it is possible for you to spend some money on the machine, then getting more RAM into it will provide you with a noticeable win, though. I am here answering from an only 3 MiB L2 cache CPU driven laptop with 3 GiB of RAM, and this is fine for getting my office work done. I also have a more powerful machine with a CPU comparable to yours, coming with 8 GiB of RAM installed there. For now I did not consider to upgrade it. I get all my daily many-tabs-browsing and small programming tasks flawlessly done on it. I would need to consider an upgrade, if I would be interested in compiling apps from larger code sources, or if I would need to run image processing and image analysis tasks, in general if I would have needs where the high throughput of data through the motherboard, disk controller, network hardware, RAM and CPU is of importance.
>
> Best wishes, Marco.
>
Thanks for your comprehensive explanation. It looks very fine then.
Since you're using Debian from a USB, the results might be
even better if the system were entirely on the hard disk.
My last doubt is if should use Debian 10 with KDE Plasma or Debian Bullseye instead.
Apparently, only the newer versions of KDE Plasma have the performance boost.