What does Class 4 Sim mean?

[Lesharo Constantine]

A friend of mine is looking to buy a sim, but we have no clue what the classes mean.  I've seen "Class 5 Sim" and "Class 4 Sim" but what does that mean exactly?

[Ayumi Cassini]

The classes simply specify what set of hardware is used (the server that hosts the sim) - the higher the class, the better sim performance. Here's what Ian Linden wrote about the differences, when Class 5 was introduced:

From a resident perspective, the key difference is that the newmachines should offer higher, more consistent sim-side performance forheavily-loaded regions, especially when there are a large number ofscripts running. LSL performance should be quite a bit higher, althoughwe won’t know by exactly how much until Class 5 has been running inproduction for a while. More generally, the new servers have somefuture-proofing features for us, and use less electricity than previousgenerations.

So, here’s what’s different under the hood: we’vebeen all-AMD for years, but are moving from the Opteron 270 to theIntel Xeon 5148 - a low-power version of Intel’s new Core 2 Duo basedserver CPUs. This gives us better performance for fewer watts, whilesupporting our standard 64-bit OS image. We’ve also doubled the RAM permachine from 2GB to 4GB and moved to a faster SATA disk, which usuallywon’t make much of a difference, but should reduce the stalls sometimesseen by heavy regions during autosaves. Finally, there are fewer,bigger system fans, and power supply efficiency goes from 67% to 84%;power usage while running the sim process is about 175 watts, vs. 230for a Class 4.

Source:

[Troy McLuhan]

How can a land renter check to see if the parcel they're renting is on a region with a Class 4 server or a Class 5 server?

[Ayumi Cassini]

As far as I know, only estate owner can check this information.

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http://ayumicassini.blogspot.com

[Chaos Mohr]

While an Estate owner can check the 'class' of their sim in the Land Manager on Secondlife.com, the class indicated only shows the class of sim that is billed and not neccessarily the class of hardware the sim is actually running on. For 'most' cases, you can still tell the class of sim by the sim number found in Help > About Second Life. Where the sim number is indicated as in:  sim4658.agni.lindenlab.com - the number indicated, ie: 4658 can be used to tell the sim class most of the time. Sim numbers below 2133 are generally class 4 sims and those above are class 5's (stated in a blog post by Prospero Linden in 2008: " If the number after “sim” is less than 2133, the region you are in is a class 4 region" https://blogs.secondlife.com/community/features/blog/2008/05/15/rolling-restart-for-half-of-the-grid-friday-morning-2008-05-16)

I own a few class 4 sims and all of them are below 2000 in number, however it is possible that not all are, and there are a number of sims out there that while billed as class 4's are actually running on class 5 hardware.

[Ellla McMahon]

Moving away from server Class

Posted by Jack Linden on 10-Nov-2009 18:10:54

What would we do instead?

We intend to move to a simplestandard specification that would become our baseline for all regions.Everyone owning or buying Land could be sure of being on at leastthat specification of Server, but no longer pinned to it. If higherspecification hardware is available, we could use that to improve youruser experience but no-one would ever be on less than the standardlevel.

Why do this now?

Now is the perfect time to makethis change because soon the entire Grid will be on at least class 5hardware. The grid is currently made up of Class 5 regions with a smallnumber of class 4s (2000 regions). As part of moving away from Classesof hardware, over the next few months we would move those class 4regions to class 5 hardware. Class 5 would therefore become ourstandard baseline.