This is a regular annoyance despite both host and client being on a LAN and having plenty of bandwidth and processing power (I'm using Windows 7 x64 on both.)
There is something strange about how UltraEdit (through v23.20 at least) is drawing the screen when TrueType fonts are in use. Even if I have every bell and whistle enabled - ClearType, Aero, all the fancy animations - UltraEdit alone draws slowly. Chrome, Acrobat, Word, PyCharm... they all dash along and are all using TrueType fonts with smoothing / ClearType enabled, while UltraEdit lags if a TrueType font is involved.
Just comparing two code editors, each with "themes" enabled and each using Consolas, PyCharm doesn't even stutter, while UltraEdit painfully redraws the entire page every time you scroll - whether by one line or one page - and when I say "painfully" I mean you literally see the sweep of the screen being redrawn.
(Edit: PyCharm does disable Windows animations
if it detects RDP is in use... but disabling this even system-wide has no effect on this problem.)
I tried other bitmap fonts instead - particularly Terminal (being the poor cousin of Comic Sans) and Courier (being optically awful)... the screen redraws fast with them, but try selecting something (recall I'm using themes) and watch the rendering misaligning the visual caret that's supposed to be on firm monospaced lines. Select some text and watch the line shrink... and woe betide anyone trying to read italicized comment text in Courier. Contrast this with Consolas and a theme: proper rendering, readable rendering, but slow-as-molasses rendering remotely.
That said, as a long-time user I love UltraEdit for lots of things and so I've finally found exactly one setting that makes a huge difference (and doesn't involve sacrificing a readable font that respects its caret):Edit the RDP session, and de-select "Experience -> Desktop Composition". Then start your remote session.
The windows will now have archaic borders, but UltraEdit will draw at a more user-friendly pace if TrueType fonts like Consolas are being used.
This is a workaround... and frankly it should be entirely unnecessary
. There are those that prefer things such as un-smoothed bitmap fonts, solid borders, and Windows controls from the glory days of Windows 98: please by all means use them by disabling other options as well (likewise if your connection is just plain slow).
But regardless of personal preferences, on a fast link there's zero reason for UltraEdit's screen to redraw this slowly just because the font is a TrueType one and the full suite of Windows experience options is enabled over RDP. This is buggy behavior in UltraEdit, period.
I don't know if v24 will solve this (being, as I understand it, a complete rewrite) but I strongly suspect it's an artifact of the older Windows frameworks underpinning the iterations of UltraEdit for many years now.