Many new smartphones, like the Devour, are starting to carry a new processor from Qualcomm, the MSM7627, or the similar MSM7227, which packs a less powerful Graphics Processor Unit or GPU. I've read in some sites that the Devour is faster than the Droid because the latter one's CPU is clocked at only 550 Mhz whilst the Devour is clocked at 600 Mhz, and that its GPU is a lot faster than Verizon's Android flagship phone because it runs at 200 Mhz. Let's take this step by step.
The Qualcomm MSM7627 and the MSM 7227 are part of a new class of processors based on the ARM11 design, so no, it's nowhere near as fast as the Droid's ARM Cortex A8. It is true though, that it's significantly faster than the MSM7200A/MSM7201A and similar CPUs powering first generation Android phones, but I don't think it can match the Droid. What makes the these two new chips faster? A few key aspects. They have a faster dedicated modem processor for handling calls and data connections, a dedicated floating point processor which the older ARM11 designs by Qualcomm lacked, a faster Digital Signals Processor (DSP) for processing the camera & microphone inputs, and most importantly, a Level 2 (L2) cache. Although the standard ARM11 design is ready for a L2 cache, it wasn't used in Qualcomm's previous design. As a quick reminder, the cache memory sits in between the CPU and the system's memory, trying to predict which data the CPU will need from system memory, store it and give it to the CPU when it asks for it. It is very small, but just as fast as the CPU. Since the system (or main) memory is very slow in comparison to the CPU, any improvement in the time the CPU waits to get its data from main memory results in an overall improvement in system performance. Having a larger cache, the new MSM7627 and MSM 7227 chips should definitely be much faster than its predecessors, but let's not make a mistake here; these CPUs are low-end chips manufactured by Qualcomm, and if it's performance what you want, you'll still need the extra punch provided by ARM Cortex A8 CPUs. ARM11 chips are outdated not only because of processor design and raw speed, they're also old because they're going to limit what we will be able to do with our devices in the long run, since they'll suffer more with an OS full of apps, and because they'll stop being supported and thus won't be able to run new software.
If you ask "Why are these low-end chips still so popular among handset manufacturers?" The answer is quite easy. These chips are very cheap to build, and the constant improvement in manufacturing processes means the chips are becoming even cheaper, and thus help provide a higher revenue per device for both manufacturers and carriers. Devices with old hardware are not bad by themselves, but the fact that we're being sold outdated hardware in brand new and expensive smartphones is terribly frustrating. It's like going into a computer store, and seeing the latest laptops feature an Intel Core processor, when the Core 2 is already becoming old, and we're all waiting to jump into the new Core i3/i5/i7 bandwagon. For more details on the difference between ARM11 and ARM Cortex A8 CPUs, check our second issue of TechTalk here
And what about the Graphics Processor Unit (GPU) powering the Devour? Is it really fast? Is it faster than the Droid's GPU? To be honest, I don't know. I've not been able to find out what is powering the Devour on the graphics side, all we know is that it's a 200Mhz dedicated processor, supporting the Open GL ES 2.0 specification, which should make the Devour capable of running better games than the old ARM11 powered phones. In a quick sentence, OpenGL is an open source standard software layer sitting between the apps and the graphics hardware which allows developers to make the GPU draw or render on the screen, and not worry about making their apps being able to draw for each GPU available in the market. Like OpenGL, OpenGL ES is also a standard, but for graphics hardware in embedded devices, like our smartphones. OpenGL ES 2.0 allows the developers to have more control about what is drawn on the screen than previous versions, thereby allowing developers get more performance from the same hardware as well as add new effects and deliver better graphics. The MSM7200A/7201A chip is compatible with the older OpenGL ES 1.1 standard which, to give you an idea, was supported by the first two iPhones. What's even more sad though, is that Android is currently supporting only OpenGL ES 1.0, even though we've already got devices which support the 2.0 standard, with more devices using similar chips as the Devour (the MSM7227 also meets the Open GL ES 2.0 specification) joining the club. Hopefully, the support will arrive soon... perhaps in the next Android release?
Back to our case, the PowerVR SGX 530 by Imagination Technologies inside the Droid supports OpenGL ES 2.0 and has a clock speed between 100 and 133 Mhz. But more processor speed does not mean more performance, especially in graphics. I could not find specific info on these new chips built by Qualcomm, for this post which leaves us without material to tell how powerful is the Devour's GPU in comparison. What we do know is that the Devour's GPU is definitely more powerful and flexible than the one powering old ARM11 devices, since the Open GL ES 2.0 specification requires support for more advanced features which require more horsepower. I, for one, do not believe the Devour's GPU to be faster than the Droid's. There are many variables involved in graphics hardware performance, a lot more than in CPU performance (yes, GPUs are a lot more complex), but even if both the Devour and the Droid's GPU turned out to have similar performance out-of-the-box (this would also apply to other devices with similar hardware), then this would only prove that the Droid's GPU is in fact more powerful, since the more pixels on the screen, the harder it is for a GPU to draw the same content; since the Devour's resolution is less than half of the Droid's, with the same content, the Devour's GPU will always have less pixels to "fill", requiring less power to achieve the same performance as the Droid. A test using graphic intensive apps (like games) while measuring the frames per second (FPS) or number of times the GPU can update the screen re-drawing it from scratch at the same resolution would allow us to know how much the Devour's 200 Mhz graphics chip can push.
Some computer engineering students might ask: "If the GPU does the drawing on the screen, wouldn't these new ARM11 based phones be a lot faster in all aspects of the OS?" The answer would be yes, but I think Android is currently doing the drawing for the User Interface through software (CPU) and not through OpenGL, which in the latter case would mean the GPU. Explaining how the CPU can draw all what we see in the screen and what is GPU "accelerated" and what isn't in Android is out of the scope of this post, but it's certainly worth noting that using the GPU for all kinds of rendering is faster than using the CPU, and that it could be (if it hasn't been achieved yet) a good way of improving Android's overall system performance in devices with a dedicated graphics processor.
The last question on this section would be: "Why always the Droid?" To begin with, the Droid is the obvious comparison against the Devour, but more specifically, on the pure hardware side, the Droid sets the hardware benchmark through which we recommend Android phones, because of its Cortex A8 CPU, its reasonable memory and GPU. We've not revised Snapdragon class phones with you guys, but for now you should know that the latter ones are the fastest smartphones available today, faster than the Droid.