12 votes

Intel Xeon processors: Difference between 2S/4S and S2S/S4S scalability

Based on "6.5.8.4 MPSUP: Multiprocessor Support" in Intel® Xeon® Processor E7-4800/8800 v3 Product Families; Datasheet - Volume 1: Electrical, Mechanical and Thermal (pdf, page 139): This location ...
Ouroborus's user avatar
  • 221
12 votes
Accepted

Intel Xeon processors: Difference between 2S/4S and S2S/S4S scalability

The difference between S4S and 4S is the number of QPI-Links. 4S has 2 links per CPU, S4S and S8S have 3. On a 4S system CPUs form a ring, which means for every CPU there is another CPU with which it ...
Daniel Deppisch's user avatar
11 votes
Accepted

How to check if RAM is running in ECC mode?

Today I found out that there is a commercial version of memtest86 (without the +) from PassMark that offers a free version too which thankfully included ECC-Checks. In addition it also supports DDR4 ...
comfreak's user avatar
  • 1,531
10 votes
Accepted

How can I tell the maximum threads my server can run?

Welcome to ServerFault! You have two CPU sockets, that is two physical processors. Each processor has 10 cores, each core being basically equivalent to a classic single-core CPU on its own. Each core ...
telcoM's user avatar
  • 4,618
8 votes

How to check if RAM is running in ECC mode?

Edited: Bad new from your motherboard manual... : I see you run BSD/linux, run that inside the OS; (Available for FreeNAS) dmidecode -t 17 You should have a output like: dmidecode 2.12 SMBIOS 2.5 ...
yagmoth555's user avatar
  • 17.1k
8 votes

AWS Graviton Processors: which encryption specs are hardware accelerated?

While digging around for my question, I found a solution. Sources are hard to find, but quoting a somewhat random 2018 news article: Its CPU cores are based on Arm's 2015-era Cortex-A72 designs, and ...
Josh Hibschman's user avatar
7 votes

How to check if RAM is running in ECC mode?

Using a Ryzen 7 processor, none of the mentioned tools worked for me either. However with a recent enough Linux kernel, the tools in edac-utils, edac-ctl and edac-util can read out the ECC status and ...
user415177's user avatar
7 votes
Accepted

KVM: Which CPU for VM ('host' vs 'kvm64') to use for web load?

The Proxmox wiki addresses the issue of which CPU type to choose, in part: Qemu can emulate a number different of CPU types from 486 to the latest Xeon processors. Each new processor generation adds ...
Michael Hampton's user avatar
7 votes

CPU load for high performance computing

Load average shows the queue of threads ready to run. In Linux, this includes also threads waiting for disk. It could happen that a broken NFS server could increase the load average to insane numbers. ...
Mircea Vutcovici's user avatar
6 votes

TrustedInstaller.exe Takes a lot of Memory in Windows Server 2008

I was looking into this recently on a 2008 R2 server and below is what I found: To see if trustedinstaller is doing anything have a look at c:\windows\logs\cbs\cbs.log. If everything's good ...
Steve Adams's user avatar
6 votes
Accepted

how to know if my servers should use huge pages ( memory page size )

Hugepages are interesting when applications need large mappings that they will do random accesses to, because that is the worst possible case for the Translation Lookaside Buffer (TLB). You trade off ...
Simon Richter's user avatar
6 votes

Why are server CPUs so weak and expensive?

So let's go through your opinions line-by-line then; So looking at CPUs with good single core performance. One example would be AMD EPYC 73F3 which is (according to passmark) on par with Ryzen 5950X, ...
Chopper3's user avatar
  • 102k
5 votes
Accepted

Maximum php-fpm threads per one core

You probably mean processes in the pool. This depends primarily on how much blocking does your actual PHP code. The more it just waits, the more processes you need to have, because more children will ...
drookie's user avatar
  • 8,757
5 votes

Is a machine with a single NUMA node, actually a regular (non-NUMA) system?

Modern x86 CPU architectures (AMD Opteron and later and Intel Nehalem-based Xeon and later) are NUMA capable, but they do not necessarily require to work in NUMA mode. In your specific case, you have ...
shodanshok's user avatar
  • 50.7k
5 votes
Accepted

How is RAM and CPU allocated if no manual changes are applied to an Ubuntu Server

RAM is first-come-first-serve. If userA runs 9 processes that allocate 10% of memory each, and then userB logs on, userB will see only 10% of memory left. In the event that memory is exhausted, ...
Ben Scott's user avatar
  • 380
5 votes

How is RAM and CPU allocated if no manual changes are applied to an Ubuntu Server

If you need to limit memory usage on the same server, your best bet will be to either Use two Virtual Machines, ideally KVM so that you can use the existing Ubuntu server to host the VMs. However, ...
zymhan's user avatar
  • 1,382
5 votes

Hardware errors in either CPU or RAM, what to do?

Can anyone tell me what this means? You have a hardware issue that needs to be addressed - likely memory. typing MC15_STATUS[Over|CE into google, second hit is from the unraid forums which may me ...
user9517's user avatar
  • 116k
5 votes

How to get cpu hardware id on Android systems?

Some commands to get hardware(CPU) info(Some need addition package installation and some are dependent on OS type) sudo dmidecode -t 4 or sudo dmidecode --type processor cat /proc/cpuinfo lscpu cpuid ...
asktyagi's user avatar
  • 2,934
4 votes

How do I log CPU usage per process?

The accepted answer sorts by process lifetime CPU use, not short-term CPU use. You can get the top ten process by CPU use over an arbitrary interval using top in batch mode: $ top -b -n 1 -d 3 -o +%...
Tom's user avatar
  • 337
4 votes

How to check if RAM is running in ECC mode?

I have found dmidecode results to be hit or miss, with dmidecode often reporting board "capabilities" having ECC even if non-ECC memory is installed. Similarly,edac-utils also often shows ...
Dave Johnson's user avatar
4 votes

Uneven CPU load per core

That is perfectly normal. Few processes are written to utilize more than one core at a time. When I see a process that uses more than one, it's unusual, either on my multiprocessor/multicore RHEL ...
Mike Waters's user avatar
4 votes
Accepted

How many processors are on the server?

Both sockets are already occupied. Thread(s) per core: 2 Core(s) per socket: 8 Socket(s): 2 Also, nproc lists 32 cores. Since the E5-2650 has 8 cores and 2 threads per core, this ...
Sven's user avatar
  • 99.6k
4 votes

What will happen if a CPU burst up to 100% utilization in an SMP infrastructure?

If the utilization of one of the CPU in the quad-core system happens to be 100%, and it is being fixed to the interrupt to the NIC interrupt. Will the kernel schedule another CPU that is not very busy ...
David Schwartz's user avatar
4 votes

What is the relation between IO wait utilisation and load average

(Assuming Linux, although the general concept can be applied to other operating systems.) A workload cannot be described only by the load average and %iowait. Those are metrics that only summarize ...
John Mahowald's user avatar
4 votes

2 x Intel Xeon 5645 vs 1 x Intel Core i7 3.9Ghz: what is a fundamental difference?

The Xeon is a 9 year old processor (very old) but does come with a lot of functionality designed to keep your server running for longer (google 'RAS') The only i7's with 4 cores at 3.9Ghz seem to be ...
Chopper3's user avatar
  • 102k
3 votes
Accepted

High CPU load while IDLE

The md126 device indicates that you are using Linux software RAID on the server. The resync process indicates that it is syncing the two drives in the RAID1 setup. Load average over 1 means that the ...
Tero Kilkanen's user avatar
3 votes
Accepted

How to prevent a particular CPU core from being used?

Use the isolcpus parameter on the kernel command line to isolate certain cores from user-space tasks. Quoting from kernel boot parameters documentation: isolcpus= [KNL,SMP] Isolate CPUs from ...
pdp's user avatar
  • 778
3 votes

ProLiant DL580 G7 E7 Upgrade Issue

We have just upgraded three DL580 G7's that are model 584084-001 to Xeon E7-4870 processors. We found that what mattered in our environment was the revision of the main system board (not the CPU ...
Clint's user avatar
  • 31
3 votes

Virtaul machines on Intel Xeon e5420 cpu

The Intel Xeon E5420 CPU has 4 cores, as clearly documented here; it doesn't support hyperthreading, thus it can run a maximum of 4 concurrent threads. This of course doesn't mean anything in terms ...
Massimo's user avatar
  • 71.3k
3 votes

Practical difference between SPARC vs x86

Some would argue the metaphor stillholds true, others would argue otherwise. There's clock speed, but you also need to factor in RISC vs CISC. What people get, or hope to get with SPARC, is a more ...
sleepyweasel's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible