I have some brix with realtek and run ptpd installed with fedora 25.    The corrections are in the 25 microsecond range, though there are anomalies.  These are used for wifi DUTs that go into RF enclosures.  

[root@hera ~]# tail -n 1 /var/log/ptpd2.stats
2017-11-04 18:33:46.723476, slv, 0cc47afffea87386(unknown)/1,  0.000000000, -0.000018381,  0.000000000, -0.000018463, 1528.032750001, S, 0.000000000, 0, -0.000018988, 1403, 1576, 17, -0.000018463,  0.000000000

For LAN/WAN traffic, I tend to use the intel quad server adapters in a supermicro mb desktop with 8 or more real cores.  (I think the data center class machines are worth it.)

Here's the brix info:

[root@hera ~]# dmidecode -t1
# dmidecode 3.1
Getting SMBIOS data from sysfs.
SMBIOS 2.7 present.

Handle 0x0001, DMI type 1, 27 bytes
System Information
Manufacturer: GIGABYTE
Product Name: MMLP3AP-00
Version: 1.x
Serial Number: To be filled by O.E.M.
UUID: 038D0240-045C-05F7-5C06-9F0700080009
Wake-up Type: Power Switch
SKU Number: To be filled by O.E.M.
Family: To be filled by O.E.M.

[root@hera ~]# dmidecode -t4
# dmidecode 3.1
Getting SMBIOS data from sysfs.
SMBIOS 2.7 present.

Handle 0x003E, DMI type 4, 42 bytes
Processor Information
Socket Designation: SOCKET 0
Type: Central Processor
Family: Core i7
Manufacturer: Intel
ID: 51 06 04 00 FF FB EB BF
Signature: Type 0, Family 6, Model 69, Stepping 1
Flags:
FPU (Floating-point unit on-chip)
VME (Virtual mode extension)
DE (Debugging extension)
PSE (Page size extension)
TSC (Time stamp counter)
MSR (Model specific registers)
PAE (Physical address extension)
MCE (Machine check exception)
CX8 (CMPXCHG8 instruction supported)
APIC (On-chip APIC hardware supported)
SEP (Fast system call)
MTRR (Memory type range registers)
PGE (Page global enable)
MCA (Machine check architecture)
CMOV (Conditional move instruction supported)
PAT (Page attribute table)
PSE-36 (36-bit page size extension)
CLFSH (CLFLUSH instruction supported)
DS (Debug store)
ACPI (ACPI supported)
MMX (MMX technology supported)
FXSR (FXSAVE and FXSTOR instructions supported)
SSE (Streaming SIMD extensions)
SSE2 (Streaming SIMD extensions 2)
SS (Self-snoop)
HTT (Multi-threading)
TM (Thermal monitor supported)
PBE (Pending break enabled)
Version: Intel(R) Core(TM) i7-4500U CPU @ 1.80GHz
Voltage: 1.2 V
External Clock: 100 MHz
Max Speed: 3800 MHz
Current Speed: 1800 MHz
Status: Populated, Enabled
Upgrade: Socket rPGA988B
L1 Cache Handle: 0x0040
L2 Cache Handle: 0x003F
L3 Cache Handle: 0x0041
Serial Number: Not Specified
Asset Tag: Fill By OEM
Part Number: Fill By OEM
Core Count: 2
Core Enabled: 2
Thread Count: 4
Characteristics:
64-bit capable


Bob

On Sat, Nov 4, 2017 at 6:33 AM, Pete Heist <peteheist@gmail.com> wrote:
My Flent test rig needs a refresh. I currently use two Mac Minis. The Intel with the Core 2 Duo P7550 and forcedeth Ethernet is OK, so I could possibly keep it (but no BQL support which is not ideal for some tests), but it’s time for my G4 Mini with 100 Mbit Ethernet and stratospheric clock drift to go.

So I’m searching for one or two low-cost Flent devices (client or server- which needs more CPU by the way?). Requirements:

- Gigabit Ethernet (1x ok, 2x better) with a reliable Linux driver with BQL support
- PTP timestamp support (http://linuxptp.sourceforge.net), hardware preferable
- enough CPU to accurately do Flent’s higher flow count tests like rrul_torrent or rrul_be_nflows with 64 flows (sometimes I also do these together with one or more instances of rrul_be to test host fairness)

I started a spreadsheet of what I’ve found so far here in Czech:


I’m leaning towards either one of the low-end Intel NUCs or GIGABYTE BRIX mini PCs, to which I’d add some memory and storage. But so many of these low-end devices come with Realtek Ethernet (r8169 driver?). I’m not sure how stable that driver is, if the BQL support is usable (https://www.bufferbloat.net/projects/bloat/wiki/BQL_enabled_drivers/), and I’d have to settle for software timestamp support for PTP. With a higher budget, I might go for a 1U server with well-supported Intel NICs, something like described in this setup (http://www.academia.edu/10312557/DEVELOPING_LOW-COST_NTP_STRATUM_1_SERVERS_WITH_LINUX_PTP_AND_GPS). But I can’t seem to find those cheaply (even <$1000) here.

Any thoughts or ideas on this?


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