I'm not sure what they mean by low system, but if your computer chokes on WoW at -all-, then your computer is not the highest end. Note I'm not talking about internet lag or stuff of the sort, but if you have a stable connection, you shouldn't even see twitches in Dalaran.

I have a reasonably high end computer I built, 3GH dual core, NVIDIA 9800gt (1gb vram), and 2gb of ram. I always run WoW at max graphics, and my computer often has hiccups in Dalaran (especially outdoors). Sometimes it's load speeds (my hard drives aren't the fastest ever), but sometimes I think it's just processing power.

I'm interested to see how my computer fares at Ultra.

@Magma:

Are you kidding me? I can run the most exacting PC games flawlessly at full graphics settings at 1920x1200 on my PC, but WoW still bogs down at times. It is just a very poorly written graphics engine. I might as well be watching WoW in slow motion when a whole 25-man raid lets loose with AoE.

For instance, when we've been running Naxx25 lately, we pull the entire room before Grand Widow Faerlina and just spam AoE and AoE heals. I'm lucky if I get 2 fps. The same thing happens when we do Gothik by all grouping on the live side, and just AoEing everything down when the gates open.

Dalaran is a joke compared to this sort of thing. WoW also handles this sort of thing very poorly, and better looking games handle it a lot better.

I agree with Manatank. The game engine is so old now it just doesn't have much optimization. They are supposedly doing a new engine for the graphical overall in the next expansion. Maybe we will have better performance.

Although this is far from the only (or even greatest) reason for WoW chug, one non-obvious thing is that WoW uses significantly more semi-transparent textures than more modern games. Many effects that a game designed only to run on higher-end systems would achieve with a shader, Blizz achieves with semi-transparent textures so that it will run on lower-end systems. However, this means that settings that increase the processing cost of semi-transparent textures (like anti-aliasing the contents of semi-transparent textures) have a disproportionately large effect on WoW performance. It also means that many extremely modern cards get worse perf than you might expect because the cards and their drivers are not being optimized to work with "old techniques" like large numbers of semi-transparent textures. If your drivers support different profiles for different games and you have some kind of semi-transparent texture anti-aliasing turned on, you might see if turning it off just for WoW helps. I find that WoW, on my GeForce GTX 280, takes about 50% more perf hit from going form None to Multisampled to Supersampled semi-transparent textures than more modern games.

On a related note, in WotLK, they improved their depth-sorting algorithm for semi-transparent textures at the detriment of perf. But the plus is no more objects disappearing because you're looking at them through the edge of a blade of grass.

Still, none of this is really at the root of the Dalaran problem. (you notice these more in areas with lots of trees and/or ground clutter) Dalaran - like Shatt before it and Ironforge and Orgrimmar before that - is a place where more players gather at once than anywhere else, and WoW's engine has always had trouble dealing with large numbers of players onscreen at once. I suspect it's either CPU or memory-bound, or possibly even some kind of foolishly synchronous network traffic, but I haven't got an 80 yet, so I can't do a lot of testing on my own.

Turn off your "Shadow Detail" option... My friend running an 8800 GT Ultra has problems with it on, but when it's off he's maxed out everywhere he roams. And they're just shadows, nothing too spectacular.