Amazon Web Services : M5 vs M5a vs M6g

AWS M5 / M5a / M6g Benchmak

In other words Intel vs AMD vs ARM. AWS recently released Graviton series for all their main instance types: R6g with extended memory, C6g for compute optimized and M6g for general purpose. Their offering has always been based on Intel but in the past years we saw AMD and now with Graviton 2 making AWS is based on their own chips.

Amazon Web services announces their Graviton processors as a new choice for their customers for increase their performance for a lower cost. But what’s the difference between all these solutions identical on the paper ? Let’s do CPU benchmark to answer it.


For our benchmark, we took 8CPU-32GB VM from each series:

Product Price CPU Frequency
m5.2xlarge 0.38 Intel(R) Xeon(R) Platinum 8175M
Intel(R) Xeon(R) Platinum 8259CL
m5a.2xlarge 0.34 AMD EPYC 7571 2.4-3.0GHz
m6g.2xlarge 0.31 aarch64 N/A

These data are collected by our Cloud Transparency Platform, prices are for us-east (N. Virginia) region.

Performance testing

Prime number search with sysbench CPU

Sysbench CPU can be categorized as arithmetic operations on integer.

We can observe an increase of +100% on single thread and close to 400% between M5 and M6g with 8 threads.

Encryption with AES-256 CBC

Where AMD’s performance depends of block size, Intel and Graviton are homogeneous across sizes. The ARM chip is able to encrypt at 1.2 GB/sec where the M5 and M5a respectively cap at 400MB/sec (200%)  and 900MB/sec (130%).


Product Hourly Monthly
m5.2xlarge 0.38 280 3,360
m5a.2xlarge 0.34 251 3,012 -11%
m6g.2xlarge 0.31 224 2,688 -22%

Monthly is based on 730 hours, yearly on 8,760 hours without long term subscription

Prices make no doubt, each new generation offers a lower cost and M6g owns the lowest.


Depending of your workload, Graviton offers until +400% of performance compared to the Intel analogous. Combined with a lower pricing, M6G is definitively the best EC2 choice for any CPU related workload compatible with ARM architecture.

Check out data in our Public Cloud Reference

New C5a benchmark: Performance/Price

AWS recently released the new series C5a equipped with custom AMD EPYC 7R32. We can discover here, a less expensive alternative to C5, similar to what they did with M5, R5 and T3. But cost isn’t an appropriated metric if you doesn’t take in account performance, so let’s dive into a performance/price benchmark comparing C5 and C5a.

A lower pricing

Name CPU RAM C5 C5a
large 2 4 0.085 0.077
xlarge 4 8 0.170 0.154
2xlarge 8 16 0.340 0.308
4xlarge 16 32 0.680 0.616
9xlarge 36 72 1.530 1.232
12xlarge 48 96 2.040 1.848
18xlarge 72 144 3.060 2.464
24xlarge 96 192 4.080 3.696
metal 96 192 4.080

Pricing is for East US (Ohio)

Performance a bit better

Before open the hood, there are 2 things to keep in mind about C5: CPU performance is highly variable. Behind the product names, several CPU model are sold and we actually collected the following:

  • Intel(R) Xeon(R) Platinum 8124M
  • Intel(R) Xeon(R) Platinum 8275CL

Like the new AMD EPYC 7R32, both are custom models only available at AWS. Next thing, a same CPU model works at different frequencies. Generally, Cloud Providers set their CPU frequency at baseline or turbo frequency, for Platinum 8124M, we detected values from 3 up to 3.45GHz.

Geekbench 5

Kind c5.large c5a.large
Single score 934 909
Single Integer 902 815
Single Float 949 969
Single Crypto 1267 1782
Multi score 1115 1168
Multi Integer 1049 1067
Multi Float 1200 1256
Multi Crypto 1470 1952

From a Geekbench perspective, C5a excels especially in cryptography realm which is not a subject to underestimate, nowadays encryption is something used everywhere, from volumes to HTTP connections or with any backend. Other domain are also more efficient but not with a huge gap.

sysbench RAM

c5.large c5a.large
Read 8201 9139
Write 6134 7091

RAM bandwidth is a good indicator of neighborough’s noise and as C5a has just been released its value has higher chance to be better. Then, we’ll also check regularly if C5 and C5a can still pretend the same throughput.


Viewing the results below and knowing instances’ prices are 10% lower, it’s not a surprise that C5a has better profile in terms of performance per dollar spent.

Type Hourly Monthly Multi score Perf/price ratio
c5.large 0.085 62.05 1115 17.97
c5a.large 0.077 56.21 1168 18.82

Monthly price is calculated from 730 hours.
Perf/price ratio equals “Mult-score / Monthly”


With this new original CPU model, AWS decreases their pricing again but with some performance increasement. In the past with the previous C5, we observed a lot of performance variation and it wouldn’t be a surprise if future tests pull the average performance up or down.

As the full series cannot be described by its smaller instance type, we also tested bigger flavors. Feel free to consult their performance on our Public Cloud Reference.

AWS and the volume equation

Despite being one of the the worldwide most used block storage solution, Amazon’s General Purpose SSD is far away from being a general and versatile solution. Unlike other providers selling volumes based on device type and an hourly price per gigabytes, AWS made the choice to create products adapted to usages.

EBS : The Block Storage solutions

Behind the name of Elastic Block Store, 5 storage classes are available:

  • Magnetic: Historical Block Storage solution provided by AWS. As its name indicates, this product is powered-up by spinning disk making it inherently slow: 200 IOPS and 100 MB/s. But in the end of 2000s, it wasn’t a low-cost but a general purpose.
  • Throughput Optimized: Dedicated to large chunk processing, this product aims an optimal throughput. Still with HDD but efficient for Big Data or log processing.
  • Cold HDD: In the same branch than Throughput Optimized but with lower price and performance. Useful for data with less frequently accessed volume like cached data storage.
  • General Purpose SSD: This is the common volume type used by consumers and shouldn’t be taken as a standard SSD Block Storage. Firstly GP-SSD, is capped at 16KIOPS which is pretty low for an intensive workload. Secondly, its maximum performance are constrained by a credit system not letting you benefits permanently from the best performance. These both arguments make GP-SSD more appropriate for non-intensive workloads that do not require permanent charge.
  • Provisioned IOPS SSD: It’s an answer to the changing performance of General Purpose. This product allows user to define and pay for an amount of maximum IOPS going up to 64KIOPS. It makes possible storage-bound workloads but at a high price of $0.065 per provisioned IOPS.

Local storage

Block Storage isn’t the only one solution provided by Amazon Web Services, since I3 series, local NVMe-SSD are available for High-IOPS workloads. Let’s compare similar solutions on paper: i3.large vs r5.large + 500GB GP SSD.

Flavor CPU RAM Storage Monthly price
i3.large 2 16 475GB local NVMe-SSD $135
r5.large 2 16 General Purpose SSD $168.4

As you can see on table and chart below, for an equivalent solution in term of basic specifications, it’s much more worth opt in for the i3. Also, the NVMe devices are attached locally to I3 VMs without block storage creating a real gap in terms of IOPS and latency:

Features matter a lot

To do the a comparison of Block versus Local storage is inappropriate without taking in account features. In fact, despite its general lower performance Block Storage is a key component of Clouds’ flexibility and reliability. Where a Local device may focus on latency, Block is attractive by all its features such as snapshot/backups, replication, availability and more.
Here a small comparative table outlining general pro and cons:

Block Local
Latency Low to high Very low
IOPS Low to high High to very high
Replication Yes
Price Low to very high Included with instance
Size Up to +16TB Fixed at instance startup
Persistence Unlimited Instance lifespan
Hot-plug Yes No

We see that there are clearly 2 usages: A non-guaranteed high performance and a flexible one.

Top 10s Cloud Compute debriefing

We recently release our Top 10 for Cloud Compute North America and Europe. With the help of our automated platform we tested near to 20 cloud providers and selected the most interesting per region. These studies outline performance/price value of Cloud Computes and bound Block Storages. We focus on maximum performance delivered by general purpose infrastructures, their associated costs and where is the best efficiency per dollar spent.


For each provider, we tested 4 sets of VMs:

Category CPU RAM Extra storage
Small 2 4 100
Medium 4 8 150
Large 8 16 200
XLarge 16 32 500

From all the performance and pricing data we collected, the vendor selection was agnostically done, only by numbers with the following key metrics:

  • Hourly price
  • CPU Multi-thread performance
  • Volume IOPS
  • Volume bandwidth

Inherent biases

1. Hourly prices

De facto, most of the hyperscalers are penalized by the documents’ approach. Despite they could propose computing power at the edge of technology, the design of our subject doesn’t take in account the long term billing options such as 1 year or 3 years. These options are only proposed by big players such as Alibaba, AWS or Azure and you can consider up to 60% of discount if you subscribe to them.

2. Volume throttling

Next, hyperscalers generally throttle volume performance, where small and medium size vendors let you reach 3GB/sec and/or 1MIOPS with block storage, the big players stop around 3000 IOPS. This may seem low but it is guaranteed, where the possible 1MIOPS are neither stable nor predictable.

3. Compute focused

Finally, documents focus on compute: virtual machines and volumes, but cloud providers have so much to propose and especially big players. Server-less, Object Storage, DBaaS, with the variety of existing services, the whole value of a cloud vendors cannot be just about Cloud Compute.

Our insights at a glance

For those who don’t want to read the reports, here’s a small list of the leading providers:

Provider Price Compute Storage Region
Hetzner Very aggressive Average Average Europe
Kamatera Low Average High Worldwide
UpCloud Average High Guaranteed very high Worldwide
Oracle Cloud Average Average High Worldwide

What next ?

These documents will be renewed and their methodology improved. We want to bring more infrastructure characteristics like network and RAM. In the pursuit of objectivity, we think that we must diversify our reports to answer real life problematics such as:

  • Small and medium size providers
  • Hyperscalers
  • Country based
  • Provider origin based
  • Object storage, CDNs, DBaaS, Kubernetes, etc

We also want to digitalize this kind of report. Instead of just PDF, we wish to let consumer explore data with a web application. This will also let user appreciate more than 10 vendors without decrease reading quality.

For the meantime, do not hesitate take a look at our document center.