Sequential vs Random Read

[SpeedTrainer]

First of all, what is the difference between these 2 and can I have an example of how they would come into play?

I want to buy a SSD for my PC to get a little improvement on it and help out with online gaming. I mainly play games like TERA and Blade and Soul. So which would be more important for gaming online, sequential or random read, and how would each affect it?

Lastly, I have been seeing some highly rated SSD and 1 may have better sequential read while the other may have better random read, so I need help deciding.

Thanks.

 

[popatim]

Sequesntial is when all the data is read/written sequentially (ie - its all in a row so there wont be any pauses to preposition heads)
Random is random, data scattered about whereever on a drive.

Data tends to get put in places that are empty rather the where there is room to store it sequentially. This fragments the data and hence why we ran defrag on HDD's

Normal users, including gamers, use mostly random access on their drives. This is an important metric which mostly gets overlooked when comparing drives and SSD's.

I tend to get the higher random SSD's. When you are transferring a 1MB file does it really matter if you get it in 1/520'th of a sec instead of 1/510th ?
Nope.

My patriot pyro ssd running on sata2 (max sequential is 235MB/s) boots faster then my Samgung 830 SSD on sata3 (max sequential 510MB/s) because its 4k speed is 35MB/s and the samsung is in the low 20's. (crystaldiskmark). I was amazed by the result until i figured out why, then it made sense. LoL

 

[SpeedTrainer]

Thanks for the response. As I was continuing to research an answer to my question, I came across this:

http://www.tomshardware.com/reviews/ssd-gaming-performance,2991-14.html

It appears that game startup and level loading mostly use read (rather than write) and 2 out of the 3 games tested used sequential (rather than random). As for gameplay, they all seemed to use sequential write.

This is all very confusing because most topics on forums usually say random read is best for online gaming.

 

[popatim]

All modern sata drives are going to seq read/write in the 500MB/s range. + or - 20 isnt going to make a huge difference (~4%) to those files which are the static files, Maps, common gear, level info... Like I said, I dont care if a 50MB file loads in 0.1s or 0.08. I can't 'see' a 0.02 sec lag.

The random comes in when you are moving around and the game has to load the individual pieces that other players are wearing. That can add up fast and would all basically be random. Hence why entering a city drops your framerate so much. Lots of data to load and cache.
An SSD random ability can range as much as 10MB/s between drives and that could be a 25% difference because random can be so slow. Now thats something that just might have a noticable impact I would think.

At least thats my thinking on it.


A bigger impact to online gaming to me is your internet IMO. Good fast internet is key to good gaming to me.