Daggerfall doesn’t need that much power, a 486DX2 was enough back in the day. So I guess there are three possible reasons why it’s not running properly:
1. Wrong configuration in mDosbox: you need to set cycles=max to get ideal performance
2. old/weak hardware: I don’t think your phone is too old, even my old Galaxy Note 2 (S3 hardware) is easily capable of running Daggerfall.
I strongly suspect you’re trying to run Dosbox on a Snapdragon chipset. As a rule of thumb, Snapdragon cpu’s are really bad for emulators in general.
My Note 4 (Snapdragon 805 @2.7 GHz) was barely capable of running any demanding DOS games. Snapdragons are horrible when it comes to NEON instructions, which, unfortunately, are of extreme importance for fast Dosbox emulation.
The Snapdragon 410 for example, which is “powering” recent phones like Galaxy A3 or A5, as well as many Huawei and HTC phones, is a good cpu in everyday use, but it only reaches a meagre 4100 realtics in the Doom Shareware timedemo. Even my Galaxy S1 was faster 6 years ago, with a 1 GHz single core Exynos cpu.
3. Conservative kernel settings:
Again, that’s mostly a Snapdragon thing. This is because of their bullshit cpu design, that requires them to downclock the cpu whenever possible, to prevent overheating. BUt it might affect other chipsets, too. If you are rooted, you can try to tweak your kernel settings. Ideally, you’ll set the cpu governor to “performance” prior to running Dosbox. Or you try different governors, and tweak their up- and downclock values. Beware that you can damage your phone, if you don’t know what you’re doing.
If you want to do some testing, download the Doom Shareware v1.9 from here. Set cycles=max in mDosbox, leave everything else at default, and run Doom with these parameters:
C:\>Doom -timedemo demo3
The resulting score shows you exactly how fast your emulated DOS machine on your phone is. You can compair it with real PCs in this list: https://www.complang.tuwien.ac.at/misc/doombench.html
A5 stock kernel settings: 4100 realtics (486 33 MHz)
A5 performance governor: 3600 realtics (486 40 MHz
Note 4 stock kernel settings: 2100 realtics (Pentium 75 MHz)
Note 4 performance governor: 1400 realtics (Pentium 90-100 MHz)
S7 Edge stock kernel settings: 760 realtics (Pentium 166 / AMD K6 233 MHz)
S7 Edge performance governor: 640 realtics (Pentium MMX 250 MHz)