Chaos Performance: https://www.fearlessrp.net/showthread.php?tid=92673&pid=815724#pid815724

Alright, let's start with V4B1 as I think it will be useful as a baseline to compare the other maps to. Anything drawn with the wireframe is what is being rendered on someone's screen, this is a debug tool used to help with visibility optimisation when making maps. Shadows have also been disabled and fullbright is on, so the map looks a lot worse than what it normally is. I am only going to be looking at performance, not at how a map looks or at functions of a building. I am going to do one map per post, as i'm easily going to reach the character limit in these posts.

Each section will gain a score out of 10. The scores mean the following:
0: No optimisation
1-3: Poor
4-6: Decent
7-10: Good

Wireframe guide:

Models: Cyan
Sprites: Green
Displacements: White
Decals and Overlays: Yellow


Areaportals: Green

V4B1

Summary: 

V4B1 is an impressive map which pushed the limits of Garry's Mod map making when it was released years ago. To push these limits, workarounds have been used which means overall performance has suffered massively. Honestly, I had no clue how bad this map once until I actually opened it up a bit ago. This map is the worst out of the three I have tested (V4B1, Chaoscity, Ranox).

I'm going to break each section down into these sections of the map: City, Industrial, Villas, Lake, Downtown, Connectivity and Nightingale.

City:

I'm surprised by how many is being drawn at once, let's start with a 360 from standing in front of the nexus.

https://youtu.be/LiJ_mZCjGk0

It might be a bit hard to see exactly what is going on from the video, so here's the main parts.

All of these screenshots below are from the view of standing at the nexus front, at the same position shown in the video.

Spoiler: View from nexus front to mainstreet front:

Everything in the city itself is being drawn at once. While this is expected for things out in the open the interesting part is the interior of buildings also being drawn. Many of the buildings on V4B1 on mainstreet use a lot of glass. While is looks nice and gives a pretty view, it also means that the game can't hide things behind them. As a result, all the shops on mainstreet have their interiors fully drawn. This isn't what is surprising about the map though.

Areas which are completely out of view, such as the interior of tides and the section behind bank, are also being drawn.

Spoiler: Closeup of tides:

Source provides us with multiple debug tools, one of these is the ability to lock what is being drawn (PVS) to move around and get closeups. 

[spoiler="Locked closeup view from inside tides (still only showing what is drawn while standing at nexus front):"]

[/spoiler]

As we can see, pretty much the entire interior of tides is drawn. This is extremely bad in terms of performance. Even some of the rooms are being drawn: 

Spoiler: Room of tides being drawn when standing at the nexus front:

I was extremely surprised by this. After looking into it further, tides does not contain a single areaportal to filter what the player is rendering.

It gets even worse after we look at what is being drawn behind us when we're looking from the nexus front.

The entire nexus upper floors are drawn from anywhere within the city. I'm not even kidding.

Spoiler: Nexus all being drawn from standing at the nexus front

Spoiler: What is being drawn in the courthouse room when at the nexus front:

The nexus also doesn't contain a single areaportal to filter the players view. Areaportals are basically invisible walls which the engine uses to decide what the players should render. To keep it simple, if the player can't see the areaportal it won't render anything behind it. It is commonly used in door frames, tunnels and windows. 

We're not even done yet. All of apartments and park are also drawn due to the glass windows on the nexus. Even though the player is at the nexus front, they are able to view apartments and the park from the nexus windows. This is the result:

[spoiler="Rendered objects at Park + Apartments from nexus front"]

[/spoiler]

Spoiler: Rendered objects at apartments from the nexus front

On the bright side, izzies palace does infact contain an areaportal (the green thing visible at the door). This means we're not rendering things inside of it.

Spoiler: Izzies front view

We haven't even moved from the nexus front yet and we're pretty much drawing the entire city. This explains the poor performance on V4B1 in the city. Enough of the nexus front though, let's start moving through the city.


Flythrough of the city at road-level, entering from connectivity:
https://youtu.be/0PxrXkeCsH4

I'm aware the video quality seems low, this is just due to youtube's compression and many things being displayed at once.

The only well optimised place in the entire city is the jails and office building. These both used closed designs with no windows, which means visleaves and areaportals can be used effectively. Even this isn't done correctly by the map creator, as shown below.

Spoiler: Garage being decent, still showing some things outside though

Spoiler: Jails being poor

This is all extremely weird, as the creators of evocity are very talented map makers. This leads to me believe a lot of optimisation may have been lost in the workshop re-upload (as the map was split for filesize reasons) but may still be in the original map. However, I can only judge from what the current workshop version is.

City overall score:

1/10, the city is horribly optimised with the majority of all objects being rendered at once while within it. This is due to the poor level design with glass being overused, especially in the nexus. Even sections which should be well optimised aren't which leads me to believe there's an issue with the workshop version being used and not the map in general.


Connectivity

Connectivity appears to be well optimised at first glance due to areaportals at each tunnel.

Spoiler: Connectivity Road

Connectivity warehouse however still renders everything outside of the building, meaning I have to reduce the overall score.

Spoiler: Connectivity Warehouse

Connectivity overall score:

7/10, it's a minor area and most people are just going to drive past it anyway. Connectivity warehouse really does bring its score down but it does look like some attempts are made to optimise this area. It also really isn't many things to render, so it works fine.


Industrial

Here's the view looking from Industrial Tunnel:

Spoiler: View from Industrial Tunnel

This is already looking a lot better than the city, i'm going to lock the render to stay at the tunnel and look at what is being drawn.

The interiors of some buildings are slightly drawn, but overall it seems like they have been optimised well:

[spoiler="View of front warehouses, rendered only as if you're at tunnel"]

[/spoiler]

The back half of industrial isn't even being drawn as the game understands we cannot see it at all:

Spoiler: Back half of industrial, rendered as if we're at the tunnel

There's only two issues I see with Industrial:

1) The big factory interior is always rendered

Spoiler: Big factory interior rendered while we're at tunnel

2) The back part of the main MTL building is rendered even though we cannot see it

Spoiler: MTL main back rendered while we're at tunnel

Industrial overall score:

9/10 - It's well optimised for a closed area, the only thing that lets it down is the big factory.

Downtown

Here's the view looking from the connectivity tunnel:

Spoiler: View from tunnel

All of the motel is rendered upon entering.

Spoiler: Motel closeup from tunnel

This does make sense as the windows are all visible. If we could edit the map, I would simply move it a bit to the left.

Spoiler: View from outside motel down the road

Now for some reason only the trees directly outside of the club have LOD. This means that the further away the player is, the more they decrease in quality. This is a common feature on trees due to them being complex geometric structures. For some reason, V4B1 lacks this massively with pretty much all trees apart from the ones directly outside having no change in LOD.

I think the club does an alright job at making sure it's only rendering what the player can see, it's obvious attempt has been made to to optimise this portion of the map.

Spoiler: Club hiding props which aren't visible

The other building has a lot of windows, which means props are drawn when you're driving past.

Spoiler: Other building drawing props

This is a bit annoying as there are quite a few props inside, it isn't a major issue though as there's not much else the client has to render here.

Downtown motors is a simple building and it doesn't draw what's inside if the player cannot see.

Spoiler: Downtown Motors

The only issue here is little village, which is completely rendered even when the player has no view of it.

Spoiler: Little village ingame view

Spoiler: Little village render view

The houses are quite simple and there's really not many props here, so it shouldn't be the cause of any performance drop. The houses themselves do hide whatever is inside if the player has no view of them anyway while inside the village.

Downtown overall score:

5/10 - It's honestly decent as while it isn't the best in terms of optimization and little village is rendered whenever someone is close, it really shouldn't result in any performance drop due to the density of props in the area being quite low.

Nightingale 

Spoiler: Rendered objects when entering from connectivity tunnel

This is a very simple area so this will be quick, when entering the walls of the hospital are rendered pretty much straight away. The entire thing renders when you're about halfway up the road before the bend. The only issue I would say with this area is the hospital shouldn't be rendered as there's a wall in front of it anyway. By extending the wall upwards a bit the entire thing could be hidden, making this section well optimised. 

Spoiler: Hospital wall view

Nightingale overall score:

7/10 - It's not the best but it really isn't bad either, it's a basic area with not much being rendered inside. I'm pretty sure the creators could have gotten away with just an areaportal at both tunnels if they really wanted to, it is nice to see the hospital does have some optimisation work put into it though.

Lake

The lake is a massive area, so this is where the render distance actually plays a massive role in making sure not too many things are being rendered at once. 

Spoiler: View from nightingale tunnel to lake left and right side

All the houses in the lake area only show props which are visible.

Spoiler: Lake cabin 2 front view and side view.

The only real complaint I have with the area is that only some trees have LOD.

Spoiler: Only some trees have LOD

The tree with a box around it has turned into a 2D picture due to us being so far away, while the other smaller one next to it hasn't changed at all. All trees supporting this could result in a massive boost in FPS on the map, as they're very common.

The only issue is with the windowless houses at the lake village, with things outside being rendered even though you cannot see them at all.

Spoiler: Outside rendered from inside lake house

Lake overall score:

6/10 - The only issue here is the trees and some of the houses, the render distance however does massively help here due to the size of the lake. There's also a random tree trunk in the road.

Spoiler: Random tree trunk in the road

Villas

Spoiler: Views from around the villas

The focus is going to be on the villa houses, as the area isn't used for much more than large dupes or basing. 

Performance on the outside is as expected, with props not being drawn unless they are visible from a window. The main issue is from the inside.

From the center of the room, the entire back portion is visible.

Spoiler: Villa house 1 center

After moving slightly up to the wall, it then stops drawing it.

Spoiler: Villa house 1 back wall

This is true for all of the villa houses, leading me to believe PVS has not been set up correctly in this area (each area should be the entire room). This means there will be a reduction in performance in the villas and potential freezes. This is because the game is always loading and unloading the things outside the rooms as you move around the villa, which is likely worse than if it was just drawing everything all the time. My GPU usage spikes to 90% as it keeps having to loading and unloading everything around it, I can imagine this can potential cause "lag spikes" for some people with worse GPUs.

Villa overall score

2/10 - The villas area is quite basic, however the constant loading of textures means performance suffers in this area.

V4B1 conclusion/TL;DR

City Score: 1/10
Connectivity Score: 7/10
Industrial Score: 9/10
Downtown Score: 5/10
Nightingale Score: 7/10
Lake Score: 6/10
Villas Score: 2/10

Map overall: 3/10

The central area of the map is very poorly optimised. The city contains the most players, props and entities most of the time too. This means most players will have an extremely low FPS in the city causing them to not want to play.

I'll do ranox and chaoscity later, this one just took way longer than expected.