Broadwell-DT: Initial Thoughts

The new Broadwell desktop processors are somewhat out of sync with our regular expectations from Intel. Due to issues surrounding the 14nm node, as well as the cost, the whole Broadwell line from tablet to table-top has come out slower and more staggered than any Intel release in recent memory. As a result, the initial launch from Intel today is a pair of 65W desktop socketed models backed up with three 65W soldered down models whose true heritage is a chip primarily designed for large laptops and all-in-one devices.

Normally we would expect a range of desktop models from 35W up to 88W or higher, but socketed Broadwell-DT today only exhibits two units at 65W. This immediately puts a slight damper on those expecting to upgrade from Haswell’s high-end, or those wanting to go from something like a Pentium G3258 on Haswell to Broadwell’s top SKU. As a result, we have to keep our expectations in check – 65W should on paper perform nearly as well as an 88W part would, except it would be reduced by several hundred MHz. Meanwhile as these processors are also fully-unlocked and overclockable, we're left to ponder whether or not the stock frequencies actually matter in that case.

Due to the differential tangent at play, these processors also exhibit Intel’s best integrated graphics package, Iris Pro (GT3e), previously reserved only for soldered down/laptop/mini-PC orientations. This graphics package comes with largest number of execution units available from Intel, 48, alongside 128MB of eDRAM that acts almost like an L4 cache. This helps alleviate memory bandwidth pressure by providing a large(ish) pool near the CPU but with lower latency and much greater bandwidth than main memory. The eDRAM has the greatest effect in graphics, but we also saw some moderate increases in our non-3D regular benchmark suite.

The benefit of the graphics package, Iris Pro 6200, means that Broadwell-DT takes the crown as the fastest socketed graphics available. Our testing showed that the even the second-tier socketed SKU, the i5-5675C, outgunned the previous title holder, AMD’s A10-7870K. Despite having the i7-5775C in to test, due to time and firmware issues, we were unable to run the numbers on the integrated graphics but will do so in a later piece.

The key element to Broadwell-DT is not to consider it a natural successor to Haswell. It doesn't so much replace Haswell-K at this time, so much as it occupies a space Intel has left neglected since the launch of Haswell – the ultimate Intel integrated graphics solution. For users on integrated graphics, where money is no object, Intel now offers you the option to combine the regular CPU performance associated with Intel and a GPU that has the added performance benefits of on-chip, high-bandwidth eDRAM. The only question is whether that combined performance is worth the potential cost, and some would say no, pointing at a combined APU + GPU solution for equivalent or better gaming performance for the same price.

Pricing for the i5-5675C is listed as $276, slightly higher than the price of the i5-4690K which is at $236 on Amazon (reduced from $265). The i7-5775C is a bit higher at $366, also a margin higher than the i7-4790K which is $339 (reduced from $380). This makes Broadwell a tough sell right now in most circumstances unless you are absolutely limited to integrated graphics and want the best solution possible in a configurable PC. Given that Intel has also mentioned Skylake in their recent Computex keynote, it implements an abnormal situation that Intel has never been in with a new platform being talked about in the same breath. We have been told that these parts exist because users wanted them, and it has been interesting to see just how the added eDRAM changes the performance with discrete graphics in the mix.

Gaming Benchmarks: GTX 980 and R9 290X
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  • jimbo2779 - Tuesday, June 2, 2015 - link

    I could be wrong but I doubt the difference will be huge or even noticeable In most games and setups.
  • Refuge - Tuesday, June 2, 2015 - link

    I wouldn't purchase one of these with those intentions to be honest. They are DX11.5 not 12, and we've yet to see how well DX12 makes all the dGPU's and iGPU's play yet in the real world.

    But I also can't afford to be that early adopter anymore either.
  • XZerg - Tuesday, June 2, 2015 - link

    it would be good to note the month each series of the cpus were launched as that would really tell the story better.
  • MrSpadge - Tuesday, June 2, 2015 - link

    Ian, a point for the OC review: Broadwell-C is listed as only supporting DDR3L-1600. You even underclock your memory for the stock review. What about higher memory speeds and voltages? Is it as painless as with older K series CPUs? The fat iGPU can certainly use more bandwidth despite having Crystal Well. And anyone profiting from Crystal Well as CPU cache could also use more bandwidth. Einstein@Home is a prime example for this.
  • watzupken - Tuesday, June 2, 2015 - link

    I feel Intel is creating way too many models with slight differences.
  • MrSpadge - Tuesday, June 2, 2015 - link

    I don't disagree, yet your comment seems oddly out of place under the review of 2 chips with features we have never seen combined before:

    14 nm Broadwell (energy efficient, better IPC than Haswell)
    overclockable (the stock speeds are far too low, yet it already sometimes beats or ties the mighty i7 4790)
    Crystal Well (it's going to rock in some applications)
    twice as much GPU power than ever before in a socketed configuration (it's going to be a fine OpenCL 2.0 number cruncher for some use cases).
  • AtenRa - Tuesday, June 2, 2015 - link

    At what settings did you run memory on the AMD APUs and why only 720p on the integrated Gaming benchmarks ???
  • Novacius - Tuesday, June 2, 2015 - link

    I'd like to see a comparison to Haswell's GT3e, too. Will there be one?
  • CFTheDragon - Tuesday, June 2, 2015 - link

    Anyone know a US Retailer with the i7-5775C in stock? I have everything else ready for my build, Motherboard, RAM, Gfx Card, etc. Just need the CPU and I have been patiently waiting for these.
  • Refuge - Tuesday, June 2, 2015 - link

    They shouldn't be available publicly until about the end of the month. But you may find some early ones if you keep an eye on the right channels.

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