Intel Broadwell Thread

[DrMrLordX]

What else do you expect? With memory configurations like DDR3-2400 those iGPUs can't even make proper use of 512 GCN shaders.

 

[Sweepr]

PurePC tested Core i5-5675C and Core i7-5775C and compared them to Skylake/Kaby Lake in modern titles. As you can expect Broadwell-C stacks up favorably overall. In Deux Ex: Mankind Divided, Watch Dogs 2 and The Witcher 3 it's actually faster than Core i7-7700K (stock vs stock).

https://www.purepc.pl/procesory/broadwell_niszczyciel_test_core_i5_5675c_i_core_i7_5775c

 

[DrMrLordX]

If Intel brings eDRAM to 6c/12t Coffeelake then they might have an interesting product. That's just the sort of gimmick that they need to reinvigorate their desktop CPU lineup.

 

[Head1985]

PurePC tested Core i5-5675C and Core i7-5775C and compared them to Skylake/Kaby Lake in modern titles. As you can expect Broadwell-C stacks up favorably overall. In Deux Ex: Mankind Divided, Watch Dogs 2 and The Witcher 3 it's actually faster than Core i7-7700K (stock vs stock).

https://www.purepc.pl/procesory/broadwell_niszczyciel_test_core_i5_5675c_i_core_i7_5775c

Yeah..but they killed skylake/kaby with super slow 2133mhz ddr4.
Its faster in games at 4.2Ghz than 5Ghz kabylake.But there is huge memory bottleneck on skylake/kaby.We all knows that 7700stock with 3000mhz ram is 20% faster than 7700k at 4.8Ghz with 2133mhz ram.
https://youtu.be/43g3OTK2AbE?t=298

 

[coercitiv]

PurePC tested Core i5-5675C and Core i7-5775C and compared them to Skylake/Kaby Lake in modern titles. As you can expect Broadwell-C stacks up favorably overall. In Deux Ex: Mankind Divided, Watch Dogs 2 and The Witcher 3 it's actually faster than Core i7-7700K (stock vs stock).

1. Open review.
2. Check test system.
3. RAM speed DDR4 2133 CL14.
4. Close review.

 

[Sweepr]

Valid point, they should have used DDR4-3000+ for Skylake/Kaby Lake.

 

[Arachnotronic]

If Intel brings eDRAM to 6c/12t Coffeelake then they might have an interesting product. That's just the sort of gimmick that they need to reinvigorate their desktop CPU lineup.

How much extra would you pay for an eDRAM version of a 6C/12T CFL?

 

[Edrick]

How much extra would you pay for an eDRAM version of a 6C/12T CFL?

Whats the point? 6C/12T Skylake-X will have quad channel memory and larger caches, which should remove all memory bottlenecks that current skylake CPU have with dual channel memory.

 

[Arachnotronic]

Whats the point? 6C/12T Skylake-X will have quad channel memory and larger caches, which should remove all memory bottlenecks that current skylake CPU have with dual channel memory.

You cut right to the point that I was going to try to make in a series of questions

 

[AtenRa]

6-core Skylake-X is not the same as 6-core Coffeelake (dual Channel smaller L3)

 

[Drazick]

I think in modern computing what holds the CPU back (Mostly) is the Memory Bandwidth.

Modern Intel CPU (Any CPU which supports AVX 2) can have amazing FLOPS number.
Yet it requires using SSE & AVX.

Yet usually when the code is written using SSE & AVX the CPU easily (If the stream of data is long) saturates the Cache and then is limited by Memory Channel.
This is why eDRAM / Higher Frequency Memory improves performance noticeably for Modern Optimized Code.

The next CPU Sub System Intel should optimized to give us better performance is the Cache & Memory.
The sooner, the better.

 

[coercitiv]

6-core Skylake-X is not the same as 6-core Coffeelake (dual Channel smaller L3)

Yes, but if you're willing to pay a bit more for 6c CFL with eDRAM, you might end up with SKL-X instead!

 

[crashtech]

I didn't think that quad channel DDR4 would exceed the bandwidth of eDRAM except at the very highest speeds, even then one has to imagine that the eDRAM would have an easier time staying closer to the theoretical bandwidth than the OCed DDR4.

 

[mikk]

Bandwidth isn't really the big strength of Intels edram, Quadchannel with a fast DDR4 should be better in this regards.

 

[Edrick]

Yes, but if you're willing to pay a bit more for 6c CFL with eDRAM, you might end up with SKL-X instead!

Bingo! (Plus you will get more PCIe lanes and AVX512)

 

[LTC8K6]

Intel isn’t providing much detail on the connection to Crystalwell other than to say that it’s a narrow, double-pumped serial interface capable of delivering 50GB/s bi-directional bandwidth (100GB/s aggregate). Access latency after a miss in the L3 cache is 30 - 32ns, nicely in between an L3 and main memory access.

The eDRAM clock tops out at 1.6GHz

Those are the Broadwell eDRAM specs according to Anandtech.

 

[Lepton87]

I didn't think that quad channel DDR4 would exceed the bandwidth of eDRAM except at the very highest speeds, even then one has to imagine that the eDRAM would have an easier time staying closer to the theoretical bandwidth than the OCed DDR4.

I don't think that it's the bandwidth that's important in this case but rather latency that you can't improve by simply adding more channels that's why quad channel memory doesn't bring a lot of performance in hw-e/bw-e over running dual channel. In case of haswell-e to really make good use of that 4 channels of memory you have to overclock the uncore fortunately that won't be the case for skylake because the uncore runs at the core clock by default.

 

[crashtech]

So then it's still an open question whether eDRAM could help a quad-channel DDR4 system?

 

[Lepton87]

So then it's still an open question whether eDRAM could help a quad-channel DDR4 system?

Of course it would help. remember that it doesn't need to have higher bandwidth than DDR4 because it doesn't replace it but adds additional bandwidth on top of that and not only that but it also has lower latency which measures up right between L3 and system ram.

 

[DrMrLordX]

How much extra would you pay for an eDRAM version of a 6C/12T CFL?

Maybe $25-$50? You're missing the forest for the trees, though. You get all the people sitting on the sidelines with <insertolderIntelproducthere> snidely dismissing yet another Intel release as "nothing new" to buy your chips for at least one generation.

Whats the point? 6C/12T Skylake-X will have quad channel memory and larger caches, which should remove all memory bottlenecks that current skylake CPU have with dual channel memory.

You shell out a massive premium to get that, and you wind up paying for more than just extra memory bandwidth. Intel can integrate eDRAM caches into their mainstream chips without expanding the DDR4 PHY, adding PCIe lanes, adding AVX512, etc. Hell eDRAM-equipped Coffeelake probably wouldn't need RAM running faster than the standard speed (for CFL it'll be, what, DDR4-2400 or DDR4-2666?) to perform. People keep saying, run Skylake/Kabylake with DDR4-3200 or better, and as an enthusiast I appreciate that . . . but some shlub who runs the minimum (like the aforementioned reviewers showing Broadwell-C beating Kabylake) doesn't always do that.

So not only do you save money on platform, but eDRAM lets you save money when picking RAM too!

 

[AtenRa]

Yes, but if you're willing to pay a bit more for 6c CFL with eDRAM, you might end up with SKL-X instead!

I highly doubt it,

1. 6+2 Coffeelake Desktop die will be a lot smaller than 10C Skylake-X. Actually 6+2 Desktop Coffeelake die will be smaller than Broadwell 4+3e Core i7 5775C and that CPU was selling for $366 when Intel 14nm was more expensive with lower yields.
2. Socket 2066 motherboards will be way more expensive than Socket 1151.

Also, Coffeelake power consumption will be lower than Skylake-X.

 

[IntelUser2000]

So not only do you save money on platform, but eDRAM lets you save money when picking RAM too!

Intel tends to not cannibalize their products. It's likely if that'll keep few users off the HEDT platform, then less incentive for such a product to exist.

If anything, eDRAM will come to desktops because Xeon chips that the HEDT chips are derived from will start to use them. Broadwell-C probably only existed because it was a derivative of something they'd have done anyway - Laptop chip meant for Apple with a beefy iGPU.

Also from the benchmark only games are showing the difference. I think people are exaggerating that it'll make such a difference that it'll revive the PC desktop sales. Or something.

 

[Edrick]

I don't think that it's the bandwidth that's important in this case but rather latency that you can't improve by simply adding more channels that's why quad channel memory doesn't bring a lot of performance in hw-e/bw-e over running dual channel. In case of haswell-e to really make good use of that 4 channels of memory you have to overclock the uncore fortunately that won't be the case for skylake because the uncore runs at the core clock by default.

You also fail to mention that Haswell did not benefit much from OCing memory the same way Skylake does. Skylake is a different beast. Keeping that in mind, I think it is safe to say that Skylake-X will benefit from quad channel much more than Haswell-E did.

Now I am not saying that eDRAM won't make a difference, I,m sure it would. But the question is how much of a difference for the cost it would more than likely add.

 

[Edrick]

You shell out a massive premium to get that, and you wind up paying for more than just extra memory bandwidth. Intel can integrate eDRAM caches into their mainstream chips without expanding the DDR4 PHY, adding PCIe lanes, adding AVX512, etc. Hell eDRAM-equipped Coffeelake probably wouldn't need RAM running faster than the standard speed (for CFL it'll be, what, DDR4-2400 or DDR4-2666?) to perform. People keep saying, run Skylake/Kabylake with DDR4-3200 or better, and as an enthusiast I appreciate that . . . but some shlub who runs the minimum (like the aforementioned reviewers showing Broadwell-C beating Kabylake) doesn't always do that.

So that same shlub (not an enthusiast) is going to dish out $375-$400 (guessing) for a cpu with 6 cores and eDRAM? I am just asking. I am thinking this is a great product idea for people on these forums (6 cores + eDRAM), but the market may not be there for the price they would have to charge.

Lets assume the following price structure:

7700K = $350
Kabylake-X = $400-$450
Skylake-X (6) = $500-$550

Where would a this Coffeelake sku land?

 

[Edrick]

If anything, eDRAM will come to desktops because Xeon chips that the HEDT chips are derived from will start to use them.

Now that is something I would like to see. Similar to the POWER cpus.