LS2088 Plattform speed

[csabaratz]

HW: 1xLS2088 CPU (8xA72 Core:1.8GHz, Bus:700MHz) with 2x 4 Lane PCIe 3.0 (2x~31Gbit/s) 2xDDR4 memory block (64bit+ECC, 1.8MT/s=(2x115Gbit/s) There are two parallel scatter/gather DMA data transfer processes: 1. DDR4(1) write from PCIe(1) 2. PCIe(2) write from DDR4(2) What is the achievable native data throughput rate (maximum and average estimated with all overhead)? Where is bottleneck? (Our HW is in production but we have to answer to an important RFP now.)

[yipingwang]

This case has already been addressed in the case you entered in our internal system.

Please refer to the following answered from the hardware AE team.

The theoretical maximum throughput for Gen3 X4 is roughly 28Gbps.  The throughput value measured by the customer is much lower than expected.  As you know, many factors come into play when measuring performance, e.g., software that is running on system, measurement equipment, block size, …. For the customer’s system, we are not able to answer the question of where is the bottleneck.  The customer would need to perform an analysis of their system to find the bottleneck. We cannot guarantee a maximal data throughput rate as requested.  For Gen3 x4, we think the customer should be able to achieve above 20Gbps.

Have a great day,
TIC

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[csabaratz]

Dear Wang,

we are using the LS2088 NXP eval board and NXP FW and a Samsung NVME SSD

card (PCIe 3.0 x4 Lane) which can 2.1Gbit/s write speed in a PC. We arrive

only around 8Gbit/s on the LS2088 platform however I am agree with you, the

speed should be minimum around 16Gbit/s.

Note: Increasing the PCIe block size from 128 Byte to 256 resulted around

16% speed increasing to 9.2Gbit/s but it is still not enough for our

application.

Why can we not arrive the 2.1Gbps card write speed? I don't think that the

HW can't do it.

Thanks and Regards,

ZDG-ZODIAC DATA SYSTEMS GMBH logo

Zodiac Aerosystems | Control Systems

Division

Zodiac On Board & Testing

Csaba RATZ

Senior Development Engineer

Friedrich-Ebert-Straße 75, Haus 51.

- TechnologiePark

51429 Bergisch Gladbach - Germany

Tel: 0049 2204 84 4112 - Fax: 0049

2204 84 4199

Csaba.Ratz@zodiacaerospace.com

http://www.zodiac-data-systems.com

Geschäftsführer / Managing

Directors: Cécile Dubrovin,

Jean-Marie Bétermier

Registergericht / Register Court:

Amtsgericht Köln

Handelsregisternummer / Commercial

register number: HRB 47131

Von: yipingwang <admin@community.nxp.com>

An: Csaba Ratz <csaba.ratz@zodiacaerospace.com>

Datum: 09.08.2018 06:21

Betreff: Re: - Re: LS2088 Plattform speed

NXP Community

Re: LS2088 Plattform speed

reply from Yiping Wang in Layerscape - View the full discussion

This case has already been addressed in the case 00170863 in our internal

system.

Please refer to the following answered from the hardware AE team.

The theoretical maximum throughput for Gen3 X4 is roughly 28Gbps. The

throughput value measured by the customer is much lower than expected. As

you know, many factors come into play when measuring performance, e.g.,

software that is running on system, measurement equipment, block size, ….

For the customer’s system, we are not able to answer the question of where

is the bottleneck. The customer would need to perform an analysis of

their system to find the bottleneck. We cannot guarantee a maximal data

throughput rate as requested. For Gen3 x4, we think the customer should

be able to achieve above 20Gbps.

Have a great day,

TIC