i lamented last week about how one could measure the load of various objects. i would really like to know how “heavy” this texture is or how much overhead that sculpted prim is. short of creating a standalone test sim (actually a really good idea) i figured there must be some way to approximate how much impact something has
coming from Second Life over to OpenSim for Science Education work was frustrating. i started in second life and had a unique perspective as an estate owner. at one point i had 19 sims (a mix of full, homestead, and one openspace). it had residential, commercial, and mixed use sims so i saw a lot of scenarios from multiple clubs on a sim, to music venues with 50+ people, to art receptions spanning sim crossings. in my four years i feel that i had a pretty good handle on what an average sim could do
i knew that coming over to OpenSim would have challenges. bugginess, attachments poofing, hair shifting around, and scripting issues. i was psyched to cope with that. after all, OpenSim is not even beta software yet! but i also read about how an OpenSim can have 45,000 prims and that prim limits are simply a variable in the code. but to hear that number coming from Second Life gave me hope that at least the number of prims and scripts would be close to what i knew
if you say “car” to me, i picture something with 4 wheels. so when OpenSim people talk about a sim, guess what? i think “hey, a sim, i know what that is, now where is that new jar of olives“. oops, my inner dialogue . . . =p
but a sim is not a sim! not for someone who only has a second life yard stick. and i could not find a very good explanation of what would be needed hardware-wise to have a similar experience. until i ran across a resource guide on the SimHost website (click the Resource Usage and Measurement tab and this is part of what i used to write that post on estimating sim resource use)
until it gets clearly stated by hosting companies, refugees from Second Life will face some issues in trying to reset their expectations. it’s not anything done on purpose, i just think that hosting companies assume all of us are techy. for me, as an education-only focused OpenSim person, i want to build things for educational use, i don’t have a clue about what’s under the hood
it would be like having to learn how slate is quarried for chalk boards before i could use one in the classroom!
so a sim is not a sim
in Reaction Grid i currently have 6,386 total prims and 181 scripts spread out over 16 sims and that is something that one sim in Second Life could easily handle plus have 40 people dancing around. from my experience a sim in SL can handle its 15,000 prims and about 600-700 scripts. yes, it depends what the scripts are, but on my estate i saw all kinds of scripts and usage (i also had steampunk boots that were 316 prims with rotating cogs and six scripted directional jets when flying – when i hit a sim, it felt me! plus my detailed katana and awesome Enerbot follow bot that would drop nuts, bolts, beer cans, and tires when scared). so naturally that is a similar expectation i had for OpenSim (since no one could tell me what is analogous, what else could i go on?)
the 6,386 prims and 181 scripts use up almost all our RAM! after a full server restart, 1.4 GB of our 1.5 is being used. so an OpenSim sim is a far cry from a Second Life sim
i am totally fine with that as long as i have an idea going into it. if you said that the typical hosting package was four OS sims and that was about the power of one SL sim, i can work with that (and so can others)
why am i going on and on about this?
because there will be an influx of very serious people coming to OpenSim looking for educational use in particular. there are only four months left of the Teen Grid. many of those educators are going to be thinking in terms of what they have in Second Life and making a one-for-one decision for their needs in OpenSim. if they fall short on that initial decision, OpenSim risks being seen as falling short of Second Life performance
in my opinion, OpenSim performs better than Second Life
now that i understand more about how it works, i have absolutely no issues. i get better frame rates, my sim crossings are smoother, i can build 256 metre long prims, i can link way farther (like 256 metres), i can link far more prims together, i can run a higher anti-alias all the time, and it all costs less
don’t get greedy in OpenSim and think you’ll spend far less. you can spend way less but you will get less performance too
our new hosting should address the maxed out RAM issue (which was causing me great grief and an invisible body). with 8 gig of RAM, 4 processor cores, and 500 gig of disk – i am expecting the performance of about 3 to 4 Second Life sims even though we have 16 sims. in SL, your sim resources are individually tied to the server. in OpenSim, you spread the load of all your sims onto the server. so even though we have 16 sims, several of them are very light use and act as water or forest space – the “overall” impact will be that of about 3 Second Life sims of content in my mind
caveat emptor applies to you if you are looking to use OpenSim
a great virtual world experience can be had with OpenSim, but don’t think you can have that for $25 a month – not for tasks like education – for under $200 a month, you can have about the same experience as $600 in Second Life with the educational discount ($1200 without it) plus have way more space (all of this is my opinion of course and you could go cheaper if you have a server you can use)
in latest OpenSim version, my trees rezz on, not in, the ground - sweeet!
back to measuring the load of objects! Breen offered a very easy method for this last week that i tried right away and it was pure genious! i had never used fast timers and see his comment for his well explained procedure
i was comparing a prim-trunked tree to a prim-trunked tree by linking 30 of each into one object and rezzing them while using fast timers (ctrl shift 9). i found that the prim ones used about 16 ms whereas the sculpted ones used 29 ms. 3 ms does not sound like much but it is over a 10% difference. spread that out over several hundred trees and it is a factor. what a great way to estimate load (plus the graphs are pretty). thanks Breen!
Ener –
Maybe it’s time to start asking hosting providers to estimate sim capacity not in terms of CPUs or GBs, but in terms of Second Life sims. As in, for $25 a month you get a region that’s a quarter SL equivalent. For $75 a month, you get 1 SL equivalent. Something like that.
Because you’re right — no ordinary human being can do the calculations that these guys (and gals!) seem to do in their sleep.
It would also be nice if someone were to run a few benchmarks… get a group of people together, and do some load testing on an SL region, and a similarly built-up OpenSim region using different hardware configurations.
Maybe a distributed testing lab? Run by an independent company? Like the kind of thing they already have for performance testing of websites.
Ahh — I’m sure there’s someone already out there putting together a business plan for it as I speak!
– Maria
Maria Korolov
25 Aug 10 at 12:28 am
Interesting article, and the links provide some good insight.
One thing stands out, and its similar to some past investigations I did into live video streaming – the core application hosting is quite cheap, its the concurrent users. Like SL/Opensim, a few streaming users upto five is cheap, from there it climbs almost exponentially.
In the distant past, approximately 2002, a significant game came out called Battlefield 1942. What was different was the dynamic environments, the 32 concurrent players, and the on screen actions that were portrayed to all players.
The publishers Electonic Arts(EA) made the server software available for free, you just had to host it somewhere. They provided some solid documentation, including resource allaction. They had some surprising numbers…one hour of game play consumed 60mb of traffic for an individual gamer. Far in excess of other games of the time. Servers needed serious hardware and bandwidth.
Opensim is sort of at a similar crossroad. A few regions with a few visitors dropping by(at different times) is one thing, but a high concurrency visitor event is a totally difference kettle of prim fish.
Education will pave a road here, because they will be the exposure to the big events. Intermittent social spaces cant provide the justification to purchase the big hosting plans.
Breen Whitman
25 Aug 10 at 2:30 am
@Maria: quoting what a hosting package can do in terms to SL-Equivalence would help in my opinion. i am no SL slouch and considered myself well versed in Second Life. not only from owning the estate, but also doing client work and being an SL Mentor. being a mentor with a few hours a week meant being exposed to many people from all walks of life and with many purposes (unfortunately, many seemed to think i was their to be their “friend” with some getting really rude when i would not supply an IM or photo!!!) =D
i can understand that an OpenSim host may not want to compare themselves to SL but if you are trying to help people understand, then an SL-Equivalence would help people have the proper expectations. if their expectations are met, or exceeded, then you will have a customer that praises you
let customers be part of your conversation and messaging and you will become well trusted and heralded
@Breen: concurrency is a big one. inSL i had full confidence that i could have 40 people at an event and new that 50 would start to get laggy. AND everyone else knows that too! that is an important part of this
so inSL if i had an event and it was crowded and laggy, well people understood that. in OpenSim it’s more of a crap shoot
for me in Reaction Grid, there were nights where just two other people meant i was crashing like mad and i was not sure why? now i know it was RAM – had i known an SL-Equivalence then my frustration would have been reduced and rather than restarting the server over and over again, i could have reevaluated our build and modified it accordingly. 4 sims would have run like a top with their resources (and what i would recommend if asked). if you are looking to be part of a highly education focused grid, then Reaction Grid is the clear choice
Ener Hax
25 Aug 10 at 9:43 am
Very useful Ener, and the resource calculator on SimHost is good too. I think that being able to play various tunes on the configuration of sims and hardware will be one of the big advantages and key skills for OpenSim.
Neil Canham
25 Aug 10 at 10:05 am
indeed Neil! being able to have control over your resources is something foreign to Second Life people. understanding a baseline is important to have a sound foundation
once we understand it, then we can make informed choices
thanks for your outstanding blog Neil, it’s the only place i could find info on Mumble/Murmur that i could understand! =)
Ener Hax
25 Aug 10 at 1:22 pm
I have to say Ener… This post kind of depresses me a bit. I guess that means my expectations are/were rather high for a sim in OpenSim :) And no… I didn’t expect a $25 OpenSim sim to be the same as a $300 2nd Life sim, but still… One of my baseline requirements for moving out of 2nd Life is to build and develop a small grid that will allow me to have a better experience that what I have in 2nd Life. This includes the technical environment, the control, and the social aspects (knowing I will be bringing some people with me).
Every time I seem ready to pull the trigger issues like this seem to pull be back and make me rethink what I can tolerate in 2nd Life. That is something that OpenSim needs to overcome to truly be viable for a lot of people. It is a lesser of two evils.
Alec Inglis
30 Aug 10 at 11:11 am
hi Alec =) it’s hard to say on expectations. i have removed every script and every prim from our Reaction Grid sims and it still shows using 1.3 GB of the RAM!
i don’t understand what that is about! the sims and server have been restarted but clearly something is not right
so far i am happy with our SimHost grid. for $190 it seems that i get the performance of four full sims. from what Snoopy (Pfieffer?) says, one core to one sim gives close to an SL experience
we have 16 sims with the thought of about 3 SL type sims with the “fourth” being spread out among the outlying sims
certainly if we did 4 sims instead of 16 you have an outstanding experience with one core per sim and 2 GB RAM per sim! that should be screaming performance i would think
i would suggest you talk with Jim at SimHost – he is very open and has provided more for us than we have asked for
he is an admin for OSGrid and his reputation is important, so he won’t blow smoke at you
i think you can get an experience your are looking for. it’s just that when i started i should have stuck to 4 sims, not 16, with the resources at RG
Ener Hax
30 Aug 10 at 1:28 pm