The last revision of the Xbox 360,
codenamed Jasper, was supposed to fix the infamous RRoD problem. So far the Jasper has been running fine. While Microsoft never confirmed the cause the RRoD seemed to be a result of poor cooling and manufacturing issues (either at the die/underfill level or at the solder level or both).
This is the latest revision of the Xbox 360, commonly referred to as the Xbox 360 Slim thanks to its shrinking in virtually all dimensions compared to the previous white box:
The internals are mostly new, featuring for the first time a single chip with CPU, GPU and eDRAM. Prior to this motherboard revision the Xbox 360 motherboard had two discrete packages, one with the CPU and one with the GPU + eDRAM.
The old Xbox 360 had eDRAM and GPU - Xenos on a single package (right),
plus a separate chip for the CPU - Xenon (left)For those of you who don't remember, ATI originally designed the Xbox 360's GPU and called it Xenos. The GPU was the first we ever looked at that used a unified shading architecture, so there were no dedicated pixel or vertex units. The core was made up of 48 shader processors and each SP could work on a vect4 plus a scalar op in parallel. These days we'd probably call it a GPU with 240 cores, although it's a bit dated from a functionality standpoint. The GPU runs at 500MHz and is also home to the memory controller.
On a separate die, which ATI referred to as the daughter die, was 10MB of embedded DRAM along with all of the hardware necessary for z and stencil operations, color and alpha processing and AA. This eDRAM and associated logic helped Microsoft bring AA to games and improve overall performance compared to what was possible at the time with conventional architectures.
The CPU, codenamed Xenon, implemented three in-order PowerPC cores with SMT support - meaning the whole chip could work on six threads at the same time. The design was ahead of its time but given its 90nm manufacturing process it only had 1MB of L2 cache to share among all three cores. These days it isn't really considered the ideal approach to a many-core CPU. Private L2 caches with a large shared L3 cache is preferred for scaling beyond two cores.
Leading up to Jasper, each die was shrunk independently with each Xbox iteration. The table below shows us how:
With the new Xbox 360 (codenamed Valhalla), at least two, possibly all three of the die are combined and placed on a single package:
Much Prettier than the Original
Microsoft took a page from Sony’s playbook and outfitted the new Xbox 360 with all touch sensitive buttons. The eject button is much smaller but extremely sensitive, not to mention you get a loud beep whenever you hit it. There are no issues with knowing whether or not you hit the eject button.
The power button is pretty much the same way, a light tap will toggle it and send you on your way. The green ring of light apparently doesn’t turn red anymore (it only flashes green when there’s a problem? engineering meet marketing). On the bright side like Jasper before it, there is no reason the new Xbox 360 should have the same RRoD problems as the older models. As you’ll see from the dissection not only is it a new chip fabbed on a new process, but it’s apparently cool enough to require much less force exerted on it by the heatsink clamp.
The exterior is a glossy black plastic. It looks great but picks up fingerprints and smudges like the dickins. A definite problem for those of you who like to cart your 360s around.
The Xbox 360 memory units are no longer supported but there are two USB ports up front that will accept USB drives as data ]storage.
Around back you get an optical audio out, Xbox 360 AV connector, HDMI output, three more USB ports, Ethernet port and input for Microsoft’s Kinect peripheral due out later this year.
There’s 802.11n support integrated into the new Xbox 360. If you open up the case you’ll see a USB 802.11n adapter plugged into an internal USB port. This also makes me wonder if we’ll see a cheap version of the new 360 without WiFi support.
The hard drive is still a 2.5” model but now it’s tucked away at the bottom of the system (standing up) in a much smaller case. To get to it just pull back on a couple of the fins which will let you remove a part of the cover:
Yanking on the black ribbon (it takes a bit of pulling) will pull out the hard drive itself. Microsoft appears to have sealed this drive up pretty well. I’m not sure there’s a way to remove the physical drive without irreversibly breaking open the case. I had other ways of figuring out what was inside so I didn’t bother taking this one any further.
The new hard drive is a Hitachi HTS545025B9SA00 1.5Gbps SATA hard drive. It spins at 5400RPM and has an 8MB buffer. If you were hoping for a 7200 RPM drive, you’re out of luck.
And just for fun here's a comparison shot to the old HDD:
The funny part is the hard drive form factor never changed, just the case it came in.
The DVD Drive & Motherboard
I pulled all 12 screws out but left the four heatsink screws in place since I wanted access to the motherboard. With all four removed I could pull off the bottom cover leaving me with this:
The DVD drive lifts right out and you can disconnect the power and SATA cables from the unit easily just like on the older models.
This is a newer version of the Lite-On drive found in the newer Jasper Xbox 360s. They use the DG-16D2S while the Valhalla uses the new DG16-D4S.
Microsoft also outfitted the drive with a strip of rubber to help dampen vibration:
You can also remove the CGPU heatsink fan shroud at this point, it is a snug fit but it should lift straight off:
The piece of aluminum shielding in the lower left of the picture above lifts straight out, you can remove that if you want to pull out the motherboard.
The black piece of plastic in the upper right hand corner of the picture above is the HDD carrier. It’s actually mounted on a flexible mount to allow for some vibration dampening and shock resistance. There’s a single large T8 screw holding it in place, remove this screw.
The drive tray isn’t completely free yet, there’s one more T8 screw at the back of the Xbox 360 that has to be removed. It was hidden by the casing but with that off you can now access it. Remove that screw and the drive tray is free:
The Motherboard
Two phillips screws hold the fan in place. You don’t need to remove them to remove the heatsink but I did anyway:
The single large heatsink is a lot heftier than what we'd seen in previous 360s, it doesn't feel quite as cheap or as insufficient. This time around it has to do double duty cooling both the CPU and the GPU.
At this point I can easily remove the motherboard and flip it over, revealing our old friend: the x-clamp.
Place your flathead screwdriver tip here, pointing away from
the xclamp, and pry the clamp off at this point. Repeat for 1 - 2
more and the whole thing should come off easily.Unlike previous Xbox 360s, the Valhalla x-clamp isn’t a pain to remove. In fact all I had to do was slide a small flathead screwdriver in each of the four slots in the clamp and push down to make the clamp pop out. I’ve marked the area on the photo above.
With the x-clamp removed the heatsink pulls off revealing Microsoft’s Xbox 360 CGPU covered with a heat spreader. The heat spreader is great for making sure no one cracks a core while working on these things.
The chip to the left of the CGPU is the 360’s South Bridge, responsible for the SATA and USB ports in the system. The chip is marked as an A0 stepping which is usually the first stepping to come back from the fab. This is probably a pretty tried and true design by now with no bugs to worry about at this point.
Xbox 360 South Bridge (top), 16MB SLC NAND (bottom)The Hynix NAND on the motherboard is still 16MB in size. It is SLC NAND so it should last the lifetime of the Xbox as long as you don’t somehow mod it into a database server.
The third major ASIC on the motherboard is the HANA scaler/video encoder chip we’ve seen before on Jasper.
The motherboard now has two SATA ports directly on the board itself to support the new HDD tray.
