The Intel Xeon E5 v4 Review: Testing Broadwell-EP With Demanding Server Workloads
by Johan De Gelas on March 31, 2016 12:30 PM EST- Posted in
- CPUs
- Intel
- Xeon
- Enterprise
- Enterprise CPUs
- Broadwell
Memory Subsystem: Bandwidth
For this review we completely overhauled our testing of John McCalpin's Stream bandwidth benchmark. We compiled the stream 5.10 source code with the Intel compiler for linux version 16 or gcc 4.8.4, both 64 bit. The following compiler switches were used on icc:
-fast -openmp -parallel
The results are expressed in GB per second. The following compiler switches were used on gcc:
-O3 –fopenmp –static
Stream allows us to estimate the maximum performance increase that DDR-2400 (Xeon E5 v4) can offer over DDR-2133 (Xeon E5 v3).
The Xeon E5 v4 with DDR4-2400 delivers about 15% higher performance then the v3 when we compile Stream with icc. To put this into perspective: DDR-4 @ 1600 delivered 80 GB/s.
The difference between DDR-4 2400 and DDR-4 2133 is negligible with gcc.
Memory Subsystem: Latency
To measure latency, we use the open source TinyMemBench benchmark. The source was compiled for x86 with gcc 4.8.2 and optimization was set to "-O2". The measurement is described well by the manual of TinyMemBench:
Average time is measured for random memory accesses in the buffers of different sizes. The larger the buffer, the more significant the relative contributions of TLB, L1/L2 cache misses, and DRAM accesses become. All the numbers represent extra time, which needs to be added to L1 cache latency (4 cycles).
We tested with dual random read, as we wanted to see how the memory system coped with multiple read requests.
The larger the L3 caches get, the higher the latency. Latency has almost doubled from the Xeon E5 v1 to the Xeon E5 v4 while capacity has almost tripled (55 MB vs 20 MB). Still, this will result in a small performance hit in many non-virtualized applications that do no need such a large L3.
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xrror - Tuesday, April 5, 2016 - link
Even at 3.3Ghz though, they shouldn't be that slow. I'm taking a guess - if this was a student lab, and they bothered to specifically order xeon (or opteron back in the day) workstations - I'm guessing this was a CAD/CAM lab or something running a boatload of expensive licenced software (like, autodesk, solidworks, etc) and some of that stuff is horrible at thrashing on the hard drive, constantly.And I doubt your school could spring the cash for SSD drives in them (because Workstation SKU == you pay dearly OEM workstation 'certified' drive cost).
This is all guesses though. And not trying to defend - it does suck when you have what should be a sweet machine choking for whatever reason, and you're there trying to get your assignments done and you just want to smash the screen cause it just chhhuuuuuuggggsss... ;p
SkipPerk - Friday, April 8, 2016 - link
I have seen this many times, even in the for-profit sector. I once saw a compute cluster that was choking on server with slow storage. They had a 10 gb network and fast Xeon machines running on flash, but the primary storage was too slow. When they get a proper SAN it was an order of magnitude improvement.Back in the day storage was often the bottleneck, but it still comes up today.
someonesomewherelse - Thursday, September 1, 2016 - link
We ran everything in virtual machines with the actual disk images not stored locally.... and the lans in the classrooms were 100mbit, idk about the connection from the classroom to the server with the image. How's that for slow?I would have loved it if our stuff was as 'slow' as yours. The wifi in the classrooms was very fast too..... especially since I doubt anyone bothered with turning of their torrents (well I mean it's completely understandable, you are going to watch the new episode of your favorite show once you are back home and not everyone had (well has, but most people can get it now) fth with at least 100Mbit line (ideally symmetrical, but some isps are too gready with ul speeds so 300/50 is cheaper than 100/100...... and good luck getting 1000/1000 on a residential package (the hw isn't the problem since you can get 1000/1000 with a commercial (aka over priced) package..... using the same hw... basically I would just need to sign a new contract, send it back, and enjoy the faster line in 1 business day or less)...well at least there are no bw caps (if I didn't read foreign boards bw caps on non mobile connections would be something I'd think no isp could do and not lose all customers) and there's we have no dmca (or something similar) and afaik no plans for one either (if they tried to pass such a law I can imagine that you'd have enough support for a referendum which you would win with a huge mayority), even better, the methods used to catch people downloading torrents are illegal anyway so any evidence obtained with them or derived from them is inadmissible anyway and just by presenting it you have admitted to several crimes which the police and prosecution are obliged to investigate/prosecute.... copyright infringment however is a civil matter).
donwilde1 - Tuesday, April 5, 2016 - link
One of the more interesting Intel features, in my opinion, is that Broadwell carries an on-board encryption engine with its own interpreter similar to a small-memory, embedded JVM. This enables full Trusted Boot capability, which I view as a necessity in today's hackable world. Would you consider a follow-on article on this? The project was a clean-room development called BeiHai, done in China.JamesAnthony - Wednesday, April 6, 2016 - link
From what I can tell in looking over the benchmarks, there is not much of an increase in performance at all in core vs core performance speeds going from the V1 CPUs to the V4 CPUsAs if you look at the benchmarks, and calculate that you are comparing 16 cores to 44 cores, the 44 core setup is not 2.75x faster.
So while your overall speed goes up, your work accomplished per core is not increasing at the same rate.
Why does this matter? Well thanks to software licensing costs, as you add cores it gets very expensive quickly. So if your software costs (which can easily exceed the hardware costs very quickly) go up with each core you add, but the work done does not, you quickly wind up in a negative cost / performance ratio.
For quite a few people the E5-2667 v2 CPU with 8 cores at 3.5 GHz (Turbo 4) comes out around the best value for the software licensing cost.
So while Intel puts out processors that overall can do more work than the previous ones, the move to per core software licensing is making it a negative value proposition. This is why people keep wanting higher clock speed lower core count processors, but we seem stuck around 3.5 GHz for many years.
SkipPerk - Friday, April 8, 2016 - link
Although you are right for workstations, so much demand is for generic virtualized machines. Many buyers are fine with 2 ghz with as many cores as they can get. They load as little RAM as the spec requires and throw out the cheapest single core, dual thread 2 GB RAM VM they can. This is how call centers work, not to mention many low-level office jobs. They do not care about performance because this is more than enough.I have had specialty applications where prosumer 6-core or 8-core CPUs were the better deal (usually liquid cooled and overclocked), but not many buyers are licensing insanely expensive analytical software by the core.
SeanJ76 - Sunday, April 10, 2016 - link
@Xeon chips!! TOTAL GARBAGE!legolasyiu - Wednesday, April 20, 2016 - link
The ASUS Workstation/Server board with V4 boards are very stable and they have 10% OC. I am very interested how the processor with those boards.Bulat Ziganshin - Saturday, May 7, 2016 - link
>This increases AES (symmetric) encryption performance by 20-25%PCLMULQDQ implements part of Galois Field multiplication and bdw actually improved only GCM part of AES-GCM algo. neither AES nor other popular symmetric encryption algos became faster
oceanwave1000 - Monday, May 9, 2016 - link
This article mentioned that the Broadwell EP e5-v4 family has 3 die configurations. I got the 306mm2 and 454mm2. Did anyone catch the third one?Thanks.