If you are new to the seedbox world, most likely your impulse is to download 100 torrents and launch them immediately with no speed limits, seed limit, etc. If you are in private trackers where ratio is a concern, you may feel like looking for the torrents with the largest torrents with the most peers and start them immediately.
The seedbox is a high end server, with at least two HDs in a RAID setup (basically this means that the HDs are combined in such a way that the general performance is doubled). However, because torrents are very demanding in terms of input and output, there will be a point where the disks have a bad time keeping up, and the overall performance will be worse than if you launched your torrents with a bit of time between them. This has an easy explanation: When the torrents starts, space needs to be allocated for the new files. If this needs to be done for many files at the same time, the load on the server goes high for a while - and it is less responsive to other torrents and the web interface.
On the other hand, since the seedbox is always there and Xirvik accounts have plenty of space, there is no need to try to everything on the first day.
Regarding ratio, maybe the reason you got a seedbox account in the first place was to fix it in one or more sites. There are a few strategies that usually work, and a few things you should never do:
Always use fresh torrents. Because of the way torrents work, older torrents will already have many people offering it (seeding) and fewer people downloading it (leeching). Since you need to download it first before you can actually share, your ratio will always take a hit just for getting the torrent. If you are not able to share it (because there's no one getting it from you) quickly, you are making things worse.
If you see large torrents, but old, with lots of leechers (people downloading it) be suspicious. They may not be real leechers, but partial seeders. This means that they selected a few files from the torrent (not all the files) and they are sharing those files. The tracker shows these people as leechers, but they aren't actually downloading anything. So if you join one of these torrents what will happen is that you will download everything very fast, but no one will get anything from you - and your ratio will suffer a lot.
Don't start many torrents unless your account (at the tracker) can take it. If the tracker rules you must keep a ratio >0.500 at all times, and you are say, around 0.550, your initial margin is very low. If you start more than a couple of torrents your ratio will go below the threshold - at you wil not have time to recover. Instead, get the most fresh torrent that you think will be popular, and start it. Wait until your share ratio (you can see in the web interface) is better than 100%,which is the point where your ratio is going to start getting better - and repeat the operation. You can leave your torrents running for a long time if you want, so your ratio will be improving at all times.
Xirvik