Investigating Cavium's ThunderX: The First ARM Server SoC With Ambition

Selecting the Competition

In setting up our benchmarks, we chose four different Intel SKUs to compete with the Cavium ThunderX. Our choices are not ideal (as we only have a limited number of SKUs available) but there is still some logic behind the SKU choice.

The Xeon E5-2640 v4 (10 cores @2.4 GHz, $939) has Intel's latest server core (Broadwell EP) and features a price tag in the ballpark of the ThunderX ($800) along with a low 90W TDP.

The Xeon E5-2690 v3 (12 cores @2.6 GHz, $2090) is a less optimal choice, but we wanted an SKU with a higher TDP, in case that the actual power consumption of the Thunder-X is higher than what can be expected from the official 120W TDP. To be frank, it was the only SKU that was faster than the E5-2640 v4 that we had. The Xeon E5-2699v4 ($4115, 145W TDP) did not make much sense to us in this comparison... so we settled for the Xeon E5-2690v3.

And then we added all the Xeon Ds we had available. At first sight it's not fair to compare a 45W TDP SoC to our 120W ThunderX. But the Xeon D-1557 is in the same price range as the Cavium ThunderX, and is targeted more or less at the same market. And although they offer fewer network and SATA interfaces, Cavium has to beat these kind of Xeon Ds performance wise, otherwise Intel's performance per watt advantage will steal Cavium's thunder.

The Xeon D-1581 is the most expensive Xeon D, but it is Intel's current server SoC flagship. But if the ARM Server SoCs start beating competitively priced Xeon Ds, Intel can always throw this one in the fray with a lower price. It is the SoC the ARM server vendors have to watch.

Configuration

Most of our testing was conducted on Ubuntu Server 14.04 LTS. We did upgrade this distribution to the latest release (14.04.4), which gives us more extensive hardware support. However, to ensure support for the ThunderX, the gcc compiler was upgraded to 5.2. In case of the ThunderX, the kernel was also 4.2.0, while the Intel systems still used kernel 3.19.

The reason why we did not upgrade the kernel is simply that we know from experience that this can generate all kinds of problems. In the case of the ThunderX using a newer kernel was necessary, while for the Intel CPUs we simply checked that there were no big differences with the new Ubuntu 16.04. The only difference that we could see there is that some of our software now does not compile on 16.04 (Sysbench, Perlbench). As we already waste a lot of time with debugging all kinds of dependency trouble, we kept it simple.

Gigabyte R120-T30 (1U)

The full specs of the server can be found here.

Supermicro X10SDV-7TP8F and X10SDV-12C-TLN4F (2U case)

Hyperthreading, Turbo Boost, C1 and C6 were enabled in the BIOS.

Intel's Xeon E5 Server – S2600WT (2U Chassis)

This is the same server that we used in our latest Xeon v4 review.

Hyperthreading, Turboost, C1 and C6 were enabled in the BIOS.

Other Notes

All servers are fed by a standard European 230V (16 Amps max.) power line. The room temperature is monitored and kept at 23°C by our Airwell CRACs in our Sizing Servers Lab.