Intel’s Ivy Bridge (IVB) has been one of the hottest tech topics of the past 12 months — we haven’t seen this much interest in a CPU since Intel launched Nehalem. Ivy Bridge is the first 22nm processor at a time when die shrinks have become increasingly difficult, the first CPU to use FinFETs (Intel calls its specific implementation Tri-Gate), and it’s a major component of Intel’s ultrabook initiative. If all goes well, Ivy Bridge will usher in a new series of 15W ultra-mobile parts, though these won’t reach the market for a little while yet.
Ivy Bridge is a “tick” in Intel’s tick-tock model, but the company is referring to its latest architecture as a “tick+.” The reason for the change is the disparity of improvement between Ivy Bridge’s CPU and GPU components. IVB’s CPU core is a die-shrunk Sandy Bridge (SNB) with a few ultra-low-level efficiency improvements. Performance improvements on the CPU side are in the 5-10% range. Unlike Westmere (Nehalem’s “tick”), which offered 50% more cores, Ivy Bridge keeps Sandy Bridge’s quad-core configuration.
At 160mm2 and 1.4 billion transistors, Ivy Bridge is just over half the size of Sandy Bridge, with 61% more transistors. It therefore follows that Ivy Bridge’s transistor density is substantially higher than anything Intel has previously built.
Intel has decided to keep Ivy Bridge focused on lower power, rather than ramping its clock speed. Rumors have flown recently that the TDP on the Core i7-3770K has been raised to 95W, but Intel’s press materials state 77W. It’s possible that the company is planning two different versions of the chip, or that the part may have two different steppings. Either way, 77W appears to still be on the table. Intel also isn’t changing its product differentiation; there’s no way for an enthusiast to buy an unlocked CPU that also offers access to technologies like vPro or VT-d.
If Ivy Bridge’s CPU is a bit boring, the new GPU more than makes up for it. Ivy Bridge’s integrated graphics core increases the total number of execution units by 33% (to 16, up from 12), and implements support for DirectX 11, OpenCL 1.1, and OpenGL 3.1. There are now two texture units instead of one, and the GPU can issue twice as many MADs (Multiply-Add) per clock. Ivy Bridge incorporates a small, dedicated L3 cache of its own, but retains its ability to share data across the high-bandwidth ring bus that connects it to the processor, if necessary.
Other improvements include better Z-culling, an improved anisotropic filter, and better image post-processing capabilities. Intel claims its new chip can boost performance by up to 60% compared to Sandy Bridge. The Quick Sync video technology that debuted with SNB last year also gets a performance boost from these new features, and IVB supports up to three displays (up from Sandy Bridge’s two).
One of Ivy Bridge’s other features is that it’s backwards compatible with Intel’s Series 6 chipsets — with a few strings attached.
Once your motherboard vendor makes the appropriate BIOS updates available, you’ll be able to drop an IVB into an old board, or re-use a Sandy Bridge part in a Series 7 system. Intel’s stance on PCI-Express 3.0 is that you’ll have to buy a Series 7 motherboard to take advantage of it; the company has no plans to support the new standard on Series 6 or X79-based motherboards.
These limitations remove most of the potential incentive of going the hybrid route, but this level of compatibility makes it easier to repurpose hardware or upgrade systems on a budget.
We tested Intel’s DZ77GA-70K with both a Sandy Bridge 2600K (3.4GHz base, 3.8GHz turbo, quad-core, 95W TDP) and the Ivy Bridge 3770K (3.5GHz base, 3.9GHz turbo, quad-core, 77W TDP). We populated all four DIMM slots with 16GB of RAM and used Intel’s integrated graphics for the CPU comparison, in order to measure Ivy Bridge’s performance improvements. A 256GB OCZ Vertex 3 with AHCI served as storage for both systems.
When we covered the Ivy Bridge launch a few weeks ago, we detailed a number of problems we had with the motherboard. Intel sent us a new BIOS shortly thereafter and we’re pleased to note that the new chip solved the problems we encountered. The motherboard now properly detects USB 3.0 devices and can boot off SATA drives in the usual way.
As expected, Ivy Bridge’s gains over Sandy Bridge are modest. Maxwell Render picks up a hair over 10%, Cinebench a bit less.
Ivy Bridge’s synthetic 3D performance, on the other hand, is much stronger — IVB comes within a hairsbreadth of doubling SNB’s 3DMark Vantage score. We couldn’t compare using the newer 3DMark 11, as Sandy Bridge doesn’t support it, but the Vantage gains are impressive. The question is, do they hold up in real world titles? To test this, we measured both chips in three relatively new games — Civilization V, Battlefield: Bad Company 2, and The Elder Scrolls V: Skyrim.
Sandy Bridge couldn’t handle Civilization V‘s benchmarks very well, and Ivy Bridge has similar problems. Performance between the two was surprisingly static, with IVB squeezing out narrow victories. Dropping all of the game’s options to minimal levels substantially improved matters — IVB’s performance goes up to ~21 FPS in the Late Game View, but has the unfortunate side effect of rendering it pig-ugly. Switching to DX9 does no good — Civilization V is the rare game that actually runs faster in DX10/11 mode.
We’ve combined our Skyrim and Battlefield: Bad Company 2 graphs. Both games were run at 1366×768 at medium detail settings. We customized Skyrim‘s options by disabling the FSAA/FXAA that the game uses at “Medium” but left the other options at their defaults. Ivy Bridge’s performance makes a very noticeable difference in both cases; BF:BC2 frame rates jump 25%, while Skyrim‘s performance leaps 27%.
There’s no downside to these gains, but there is a caveat: Both games look pretty wretched. InSkyrim‘s case that’s easier to rectify; the FPS boost is sufficient to allow for an increased amount of detail without the frame rate plunging back into unplayable territory. With the faster-paced BF:BC2, however, that’s not an option. 20 FPS is only just this side of playable and the game still stutters.
One thing to keep in mind, however, is just how far we’ve come in a few short years. Three years ago, it wasn’t uncommon for Intel’s integrated graphics to stumble on four-year-old titles. AMD and Nvidia had much better solutions, but “better” is a relative term. None of them were up to playing the latest titles. Today, Intel’s on-die GPU can handle at least some titles released within the past 12 months.
Intel’s Quick Sync was a major component of Sandy Bridge’s unveil last year. It offers an unparalleled price/performance ratio when it comes to video encoding, easily outperforming GPU-assisted encode/decode solutions from both AMD and Nvidia. That debut was marred by Intel’s decision to split Quick Sync support between multiple chipsets — a problem the Z77 chipset happily avoids.
Intel isn’t giving Quick Sync a new label but Ivy Bridge’s version is quite a bit faster than Sandy Bridge’s already excellent performance.
Unfortunately, this graph doesn’t tell the whole story. We’re still investigating this situation, but here’s what we know for certain. Both Media Espresso 6.5 and Arcsoft Media Converter 7.5 offer an iPhone 4S preset. The quality settings of that preset change dramatically depending on which GPU is detected. The program doesn’t mention this, and while there is a “Higher Quality” option for Quick Sync users, it has no impact on the file size or quality of the final result.
This is the preset page ME displays regardless of GPU type.
Encoded with Intel Quick Sync, Stargate: Ark of Truth came to 1.86GB. Encoded with a Radeon 7950, the same film is 5.8GB. Our media analysis tool indicates that the Quick Sync version is encoded at 1.4Mbps, with a maximum bitrate of 2Mbps. The Radeon flavor, in contrast, is encoded at a constant 7Mbps. The image below shows the two outputs side-by-side; the Radeon 7950 is on the left. Click the image to enlarge it if you want a better look (large file warning).
Check the fire and the rocks at the lower-right-hand corner to see the difference
The quality difference is immediate and jumps out at you even when watching the movie, especially on a high-resolution screen inches away from your nose. Software-mode is virtually identical to the Radeon 7950 option, which leaves Quick Sync as the definitive odd man out. If you’re a blind person who enjoys listening to TV shows, Cyberlink’s implementation of Quick Sync is going to be right up your alley. Everyone else is likely to be disappointed with the final output.
If you own a Sandy Bridge-based system, you’ve got little reason to upgrade to Ivy Bridge, especially since some of the platform’s features require a new motherboard. Those with older equipment — particularly anyone still riding the Core 2 Duo/Quad bus — may finally have a reason to take the plunge. Ivy Bridge’s lower TDP will allow it to fit in smaller enclosures without compromising performance, while its enhanced 3D capabilities and better visual quality make it a more attractive as the basis for an HTPC.
Ivy Bridge isn’t just a tick on Intel’s roadmap — it’s a powerful example of how the company’s priorities have changed. It’s the first chip Intel has ever built that’s being marketed on the strength of its graphics hardware, and for good reason. While we didn’t have a Llano to compare against directly, a bit of research shows Ivy Bridge nipping at AMD’s heels when it comes to GPU performance. Long term, Ivy Bridge and its successors will have an impact on software development. In a year or two, developers will be able to assume OpenCL support will be standard across most x86 systems, no matter what hardware they use.
Intel’s focus on graphics with Ivy Bridge is an example of how the limits of semiconductor scaling have forced the company to re-examine its priorities and focus on improving performance on the areas most likely to benefit from it. IVB’s integrated GPU may not be good enough for us to recommend it to moderate gamers, but this is the first time we can fairly say we see Intel reachingthat goal in a generation or two. It’s a strong step forward on every front and it sets the stage for an impressive Haswell debut in 2013.