- 25GbE is the best choice for data centers to address the exponential growth in bandwidth needs driven by mobile data and video. - Upgrading directly to 40GbE and 100GbE is too costly, while 10GbE is no longer sufficient. 25GbE provides a cost-effective migration path as it leverages existing 10GbE infrastructure and delivers 2.5x the performance through a single lane. - A 25GbE ecosystem is developing, including standards work, available FPGA implementations from vendors like Xilinx, and the formation of a 25GbE consortium to accelerate product rollouts within the next 12-18 months.

1. Why 25GE is the Best Choice
for Data Centers
Gilles Garcia – Xilinx
Director Wired Communication Business
Santa Clara, CA USA
April 2015 1

2. Outline - update
 Data center drivers
 Why 25GE
 The need for 25GE  Applications
 25GE timeline
 25GE ecosystem
 Summary
2Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

3. The Need for More Speed
 Unrelenting IP traffic
growth
 Driven by mobile data
and video
 WEB 2.0 data
handled gigantic
Source: http://www.ieee802.org/3/ad_hoc/bwa/BWA_Report.pdf
3Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

4. Santa Clara, CA USA, April 2015 4
Service Providers
Servers
Data
Centers
Core Networking
Doubling ≈18 mos
Server I/O
Doubling ≈24 mos
- Let’s not forget OPEX and CAPEX of WEB 2.0 companies
- Increase server rack capacity and bandwidth
Multiple Drivers
Forum 1A_Garcia_Final

5. 25Gb/s Ethernet Connectivity
 Enables similar topology as 40Gb/s & 10Gb/s
• Single 25Gb/s SFP28 port implementation or
quad 25Gb/s QSFP28 breakout implementation
possible
• Maximizes ports and bandwidth in ToR switch
faceplate
• Dense rack server
• Within rack, less than 3m typical length
Server
Server
TOR
Switch
ASIC
48-port 25G 4-port 100G
Server
Server
Server
Server
Break-outcable
25G serdes
IEEE 802.3 Call For Interest – 25Gb/s Ethernet over a single lane for server interconnect – July 2014 San Diego
a) 2.5X bandwidth compare to 10G …and still through a single lane
b) One lane vs 4 for 40GE (4x10G)
c) Migration path from 10G to 25GE
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

6. Page 6
Economical Considerations
 Data centers traffic is increasing exponentially, requiring higher bandwidth
• Running out of gas with 10GE
 Upgrading directly to 40G and 100G is cost prohibitive
• Optical modules ‘cost prohibitive’ for WEB 2.0 companies
 25G leverages existing (10G, single port/lane) infrastructure
 2.5x performance per lane of twinax copper wiring between the server and the
switch
• Reduces data center CapEx by providing a migration path from 10G to 25G links
 Provides easy migration path to 50GE (2x25GE) & 100G (4x25G)
• Special server
• Uplinks
• Another 2x performance improvement
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

7.  25G Consortium formed July 2014
• Interoperability Ethernet specification for speeds between a server NIC
and top of rack switch
• Accelerate rollout of products in next 12 to 18 months
• Royalty free
• Xilinx is a member
• Founding members:
– Arista, Broadcom, Google, Mellanox and Microsoft
 IEEE 25Gb/s Ethernet Study Group progressing
Page 7
25G Ethernet Standards Landscape
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

8.  Nov 2014:
• 25GE Study Group => Task Force
 Feb 2015:
• IEEE 802.3by new 25G Ethernet draft
standard
 2016: expect standards to be finalized
– Short timeline because of reuse from
10GE, 100GE
– YE 2016
IEEE 25GE Standardization Timeline
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

9. FPGAs for 25GE
 The official 25GE standard won’t be published until YE 2016
 Robust pre-standard market today, based on FPGA implementations
 Broadcom Switch sampling with 128 25GE ports
 FPGA designs can track changes in the standards as it progresses
 The following figures shows a typical 1st generation implementation
9
MAC/PCS
Server
Copper
Cable
25GE
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

10. Xilinx Virtex UltraScale
VCU107 Board
Virtex UltraScale 25GE to Ixia Tester
OFC 2015 Demo
Page 10
Xilinx Virtex UltraScale
XCVU095
3m Direct Attached
Copper Cabling
X c e l l o n - M u l t i s 1 0 0 / 4 x 2 5 G E
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

11. Application #1:
Nx25G Ethernet to PCI Express Base NIC Card
Page 11
PCIe
Block
DMA Memory Controller
25 GE
MAC
#1
25 GE
MAC
#4
PCIe
G3x8
Nx25GbE NIC card for data center applications
• Xilinx 25G low latency solution available today
• Increases system performance enabling chip to chip solutions utilizing world class
25Gb/s serial transceivers
Q
S
F
P
28
…
3 to 5m Copper
2Km Optical
(Luxtera, Intel)
Xilinx IP
Integrated
Xilinx IP
x4
Xilinx IP
Xilinx IP
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

12. Application #2: Programmable NIC
Page 12 Redundancy not shown
Packet processing NIC card for data center applications
• Xilinx Virtex® UltraScale™ enable switchable interface between 4x10G Ethernet,
4x25G Ethernet and 100G Ethernet
• Flexible packet processing IP for customer custom logic
Bypass Path
PCIe
Hard IP
MUX
DMUX
DMA
Eng
OFF
LOAD
Classifier
Lookup
Prog
Packet
Parser
MUX
DMUX
25GbE
PCIe
G3x8
4x10GE
4x25GE
100GE
Xilinx IPXilinx IPIntegrated
Xilinx IP
Xilinx IPXilinx IP
Xilinx IPXilinx IP
3rd party IP
Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

13. 25Gb/s Technologies Readily Available
IEEE 802.3 Call For Interest – 25Gb/s Ethernet over a single lane for server interconnect – July 2014 San Diego
Page 13 Santa Clara, CA USA, April 2015 Forum 1A_Garcia_Final

14. Summary
 Data center bandwidth explosion driving the 25GE
 25GE promoted by large industry players (DC and OEMs)
 25GE demand aligned with technology single lane transceiver
 25GE ecosystem is ready for prime time
• Xilinx 25GE pre-standard MAC IP available
• Ixia 25GE tester announced at OFC 2015
• QSFP28 copper cables available
• 25GE switch silicon sampling
 25GE standards (25GE consortium & IEEE) ratification: 2016-17
 50GE is around the corner …. 50GE MAC/PCS IP available from Xilinx
Santa Clara, CA USA
April 2015 14

15. Thank You
Santa Clara, CA USA
April 2015 15