New 2011 iMacs and SL


Apple just announced new iMacs yesterday, and I’ve already gotten tons of questions about the new machines and how they’d handle SL. In an effort to offer some more detailed information, and to save myself from having to type the same thing over and over again in chats and IM’s, I’m posting it here.

For those who don’t want to do much reading....

The new iMacs are awesome. Even the base model has a pretty powerful GPU, and the high end is a powerhouse.

And now for the detailed bit.

When you’re looking for any computer, there are 4 main components to consider: processor (CPU), graphics (GPU), memory, and storage. For Second Life, the two features to really pay attention to are the CPU & GPU. It’s not that memory and storage don’t matter at all, it’s just that SL doesn’t have demanding requirements in those areas, and just about any machine you could buy today will have the bases covered. Let’s take a look at each of the four components.

In the CPU department, even the base model iMac has more than enough horsepower to handle whatever Second Life can throw at it. On a machine with only 1-2 processor cores, you’d want to pay attention to the clock speed and look for something ideally 2.2GHz or higher. Anything less, and the machine would struggle to keep up with SL, and multi-tasking (switching between a few different programs) would likely cause problems (most likely in the form of freezes and crashes as your computer came up short on resources). But all these new machines all have quad-core chips that can easily handle Second Life as well as other applications you may be interested in using at the same time.

GPU is where most people have struggled in the past. iMacs (as well as other Macs and PC’s) from several years ago often struggled with running Second Life even with quality settings turned way down, and the culprit was almost always that the GPU was lacking. In 2006 and 2007 high performance graphics power was just starting to become available, so getting something that could do everything you wanted meant a very expensive graphics card that consumed a lot of power and generated a lot of heat. Things have improved greatly in the last few years, and in 2011 each of the choices is a powerhouse.

In case the brand name confuses you, ATI and AMD are one in the same. AMD bought ATI several years ago, and kept using the ATI brand name on the graphics cards and chips. Last year, they decided that it was finally time to retire the ATI name, and starting with the Radeon 6000 series, they would only use the AMD name. But it’s the same group of people behind the designs and the drivers. Since the launch of the Radeon 4000 series, AMD/ATI has been firing on all cylinders and really doing a great job with their products, and their latest generation of GPU’s is no exception.

The first thing to point out about the GPU’s in the new iMacs is the letter M. Each of the chips has an M in its name (6570M, 6770M, and 6970M) - what does that stand for and what does it mean? M is for mobile. It’s a version of the desktop chip that uses less power and generates less heat, designed for mobile computing. Why would Apple want to put a lower power laptop chip in a desktop? Very simple - heat. Using more power and generating more heat would mean you’d need a lot of cooling fans, and you’d need a bigger case design in order to get enough airflow around all the components to keep it from overheating. In 2011 low power doesn’t mean under-powered, and each of these packs quite a punch.

On the low end, you get the Radeon HD 6570M, the same chip that’s in the most powerful MacBook Pro. It packs 400 vertex shaders, 20 geometry shaders (that’s a lot, and more is always better), has an incredibly fast fill rate (how fast it can draw pixels and fill textures), and has 512MB of dedicated video memory (256MB of which you could use for SL, the other half would be reserved for Mac OS and other applications).

The mid-range machines (the ‘big’ 21.5 inch model and the ‘little’ 27.5 inch iMac) come with the Radeon 6770M, which adds 80 more vertex shaders and 4 more geometry shaders, and has an even faster fill rate. Most measurements put the 6770M at around 15-20% more power than the 6570M, making it a very nice upgrade. It’s also got 512MB of dedicated video memory (256MB of which you could use for SL, the other half would be reserved for Mac OS and other applications).

The high end 27 inch iMac comes packed with the Radeon HD 6970M, which is an incredible GPU. It has double the number of vertex & geometry shaders of the Radeon 6770M (960 vertex and 48 geometry), nearly double the fill rate, and it packs double the video memory at 1GB (letting you use the max of 512MB for Second Life, and still have plenty of video memory for the OS and other programs). Serious content creators can even optionally go for 2GB of video memory (SL will still max at using 512MB, but you’ll have an extra gigabyte of video memory for running graphics intensive programs like Photoshop, AfterEffects, Premiere, Blender, Maya, Cinema 4D, etc). This machine is quite a content creation powerhouse in its own right, actually packing more punch than a quad core Mac Pro from a couple years ago (in fact, the Radeon HD 6970M has more shaders, a faster fill rate, and double the video memory of the ATI Radeon HD 4870 card you could add as an upgrade at the time).

Click here for an ultra-nerdy technical comparison of the GPU’s, along with listings for nearly every AMD/ATI offering in the last decade.

Memory is a much smaller issue these days, both because Macs come with plenty and because Macs handle memory fairly well. All the new iMacs come with 4GB standard, and can be upgraded to 16GB. 4GB is more than enough to run SL as well as a few background apps, but if you do a lot of multi-tasking, and like to have beefy apps like Photoshop running in the background, I’d strongly consider the upgrade to 8GB. If you do a lot of video production work or are a serious SL content creator (who would likely be getting more involved in 3D rendering over the next couple years, if you aren’t already working with it) you may want to consider stepping up to 16GB, but 90% of even the biggest SL ‘power users’ won’t need to go beyond 8GB.

Storage is almost a non-issue. Second Life doesn’t take up much disk space, and even the smallest 2011 iMac has enough room to install a copy of every viewer you could ever want to run many times over. The major decision to make with the new machines is whether you want an SSD or not. SSD’s use flash memory for storage (like an iPad or iPhone), and load much more quickly than a hard drive. How much more quickly? On a machine that would normally take 30 seconds to go from the power completely off to being completely loaded and ready to run at your desktop, an SSD cuts that time down to 15 seconds. An SSD doesn’t make your CPU or GPU or memory work any faster, but because it can get to the files stored on it almost instantly, you end up with faster performance in just about everything. SL users who’ve made the switch from hard drive to SSD (or use an SSD and a hard disk) report an increase of around 5 fps (frames per second) in Second Life. SSD’s are a lot more expensive than hard drives, so depending on your budget you may or may not want to go that route just yet.

That covers the four components, and I think you’ll agree the new machines have a lot to offer.

But what about shadows?

The short answer: Not yet. Shadows (and the newer depth-of-field feature) are still considered experimental in Second Life (click here to see a video that shows dynamic shadows and depth-of-field in SL). In the earliest stages, they only worked with a limited number of nVidia graphics cards, and not at all on any Mac (regardless of the video card). But with the release of Viewer 2.3 last fall, Mac users with nVidia cards finally got working dynamic shadows, projected lights, global illumination, depth-of-field, and other cool ‘bleeding edge’ SL features. Linden Lab has continued to hammer away at it, and does have plans to get shadows working for ATI users as well. They’re finally working for some PC users (and should work on the new iMacs running Windows under boot camp), and in the not-too-distant future I hope to see an SL update that adds dynamic shadow support for ATI users.