One of the things you learn quickly and come to hate passionately in SL is lag.
As a performer, lag is inescapable.
You’re backstage, caching dances, and then WHAM!
Suddenly your computer freezes, your screen goes black, and you begin to pray that you won’t crash.
By some miracle, you don’t crash, but moving is now like slogging through molasses.
Dancers have traded tips and tricks for years on ways to reduce lag at performances – things like:
- turn down your draw distance
- lower your particles
- turn off render for stuff like trees, terrain, sky, etc, that aren’t needed indoors
- watch your scripts – remove unnecessary ones
Venues have tried to help by asking audiences to do various things –
- sit down as soon as they arrive
- no facelights
- remove AO’s
- watch their scripts
Many venues have even installed script counters to help police the worst offenders.
But we still have lag.
So I was curious when I saw a post from Penny Patton about draw weight (ARC, Avatar Render Cost – whatever you want to call it).
In her post, Penny talks about how she was able to reduce her ARC from 200K+ down to around 50K.
Now, Penny is much more technical than I am, and I wouldn’t even attempt some of the things she does to decrease her ARC.
I wouldn’t even know HOW to do some of them.
I, like many of us in SL, am at the mercy of the content creators, whom I expect to know much more about things like textures, specular maps, polygons, and LOD than I ever will.
So after reading Penny’s post, and coming across another post on the same issue by Nalates Urriah, I decided to do a bit of testing on my own.
The post by Nalates refers back to another post (which I did not read), and states that on an ’empirical basis Kay found that jewelry is a major culprit in high ARC.’
I was curious to see what the ARC of various items in my own inventory would be.
I logged in and turned on the ARC.
You can do this yourself under the Advanced Menu > Performance Tools > Show Render Weight for Avatars. (And that is about the extent of my technical knowledge when it comes to SL!)
You will now see a number above your head – this is your ‘ARC.’
I found an outfit in my inventory and put it on.
After removing each item separately to find its ARC, here is how my outfit broke down:
- Mesh Hair: 1450 ARC
- Mesh Dress: 2744 ARC
- Mesh Feet: 1736 ARC
- Mesh Hands: 1200 ARC each (2400 ARC total)
- Mesh Shoes: 10560 ARC
- Earrings: 4345 ARC each (8690 ARC total)
- Necklace: 14482 ARC
I was not wearing any other items, other than my eyeballs, skin, and shape (I have no idea how to find the ARC of these things, since SL does not allow you to NOT wear a skin or shape).
So, I just subtracted all the items listed above from my ARC total.
Eyeballs, skin, and shape apparently account for 6308 ARC.
I was pleasantly surprised at the relatively low ARC for my mesh hair, dress, and feet.
The hands seem a little high, but I was fairly shocked by the ARC of the jewelry I had on.
It was not big, flashy pieces, just a simple necklace and earrings.
Since the other posts mentioned that jewelry was a huge culprit, I wanted to do some more investigating.
I found a jewelry set that I really love from a fairly well-known jewelry maker in SL.
I added a piece at a time to find out the ARC for each piece.
Now, let me add that this is not necessarily a scientific experiment, because sometimes the ARC would change slightly if I took the piece off and put it on again.
I don’t know if that’s because the texture is already cached?
Again, technical is NOT my forte. 😀
Anyhoo, I put on the bracelet from this jewelry set.
The ARC of the bracelet was 13603.
Almost as much as the necklace I was wearing earlier.
Then I added the left earring from this set, assuming that both earrings would be the same ARC.
Now, for some reason, I didn’t get a stable ARC from the earrings.
I got a large initial ARC, then when I removed and re-attached the earrings, the ARC seemed to fluctuate.
After several add/removes, I got the same ARC several times in a row, so I am using that one.
The earrings had an ARC of 14375 each, so 28750 ARC total for both.
So now I am at 42353 ARC for the jewelry alone, which is almost equal to the starting ARC of my entire avatar + wardrobe at the beginning of this exercise.
Then I added the necklace of the set.
The necklace had an ARC of 24235.
So for 4 pieces of jewelry (bracelet, earrings, and necklace), the ARC of the set had a grand total of 66588.
Just for the jewelry!!
With the jewelry added, I currently have the number 173388 floating above my head.
Which doesn’t make any sense, because if I add up the items separately, my total should be 91786.
So it appears that ARC fluctuates (I’m sure for technical reasons I don’t understand).
However, even at 91786, that would mean that 2/3 of my ARC is jewelry alone!
That is ridiculous.
I decided to try jewelry from a different maker.
I had two bracelets.
Each bracelet had an ARC of 15539, so a total of 31078 just for the two bracelets.
That means the two bracelets alone have a higher ARC than the rest of my entire avatar/items.
Jewelry does seem to be a huge culprit when it comes to high ARC’s.
I’m not sure what the ‘optimum’ ARC for an avatar is – I suppose it depends on your computer system.
However, I will be more conscious of my ARC when going to shows.
Wearing jewelry is nice, but not absolutely necessary, especially if I am unknowingly contributing to lag.
I have a fairly nice computer setup, so wearing all this jewelry hasn’t really affected me, as ARC (from what I’ve read and (hopefully) understood), is a factor in client-side lag, NOT server-side lag.
But I am there to see the performers, and if my beautiful jewelry is lagging them out (because perhaps their computer system is a tad older than mine), then I am ruining the show.
Do a little experimenting yourself next time before you go to a show.
Perhaps you can help avoid the lag monster as well by being more aware of not only your scripts, but your ARC. 😀
If you’re curious about how ARC is calculated, see here. I didn’t understand all of it, but light-emitting prims have a high count.
So leave your facelights at home!!!!