Micro-benchmark level performance comparison of high-speed cluster interconnects

Author(s):  
Jiuxing Liu ◽  
B. Chandrasekaran ◽  
Weikuan Yu ◽  
Jiesheng Wu ◽  
D. Buntinas ◽  
...  
IEEE Micro ◽  
2004 ◽  
Vol 24 (1) ◽  
pp. 42-51 ◽  
Author(s):  
Jiuxing Liu ◽  
B. Chandrasekaran ◽  
Weikuan Yu ◽  
Jiesheng Wu ◽  
D. Buntinas ◽  
...  

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 81
Author(s):  
Ramón Gutiérrez-Castrejón ◽  
Md Ghulam Saber ◽  
Md Samiul Alam ◽  
Zhenping Xing ◽  
Eslam El-Fiky ◽  
...  

We present a systematic comparison of PAM-2 (NRZ), Duobinary-PAM-2, PAM-4, and Duobinary-PAM-4 (duo-quaternary) signaling in the context of short-reach photonic communications systems using a Mach–Zehnder modulator as transmitter. The effect on system performance with a relaxed and constrained system’s opto-electronic bandwidth is analyzed for bit rates ranging from 20 to 116 Gb/s. In contrast to previous analyses, our approach employs the same experimental and simulation conditions for all modulation formats. Consequently, we were able to confidently determine the performance limits of each format for particular values of bit rate, system bandwidth, transmitter chirp, and fiber dispersion. We demonstrate that Duobinary-PAM-4 is a good signaling choice only for bandwidth-limited systems operating at relatively high speed. Otherwise, PAM-4 represents a more sensible choice. Moreover, our analysis put forward the existence of transition points: specific bit rate values where the BER versus bit rate curves for two different formats cross each other. They indicate the bit rate values where, for specific system conditions, switching from one modulation to another guarantees optimum performance. Their existence naturally led to the proposal of a format-selective transceiver, a component that, according to network conditions, operates with the most adequate modulation format. Since all analyzed modulations share similar implementation details, signaling switching is achieved by simply changing the sampling point and threshold count at the receiver, bringing flexibility to IM/DD-based optical networks.


Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 369 ◽  
Author(s):  
Padmanabhan Balasubramanian ◽  
Nikos Mastorakis

Addition is a fundamental operation in microprocessing and digital signal processing hardware, which is physically realized using an adder. The carry-lookahead adder (CLA) and the carry-select adder (CSLA) are two popular high-speed, low-power adder architectures. The speed performance of a CLA architecture can be improved by adopting a hybrid CLA architecture which employs a small-size ripple-carry adder (RCA) to replace a sub-CLA in the least significant bit positions. On the other hand, the power dissipation of a CSLA employing full adders and 2:1 multiplexers can be reduced by utilizing binary-to-excess-1 code (BEC) converters. In the literature, the designs of many CLAs and CSLAs were described separately. It would be useful to have a direct comparison of their performances based on the design metrics. Hence, we implemented homogeneous and hybrid CLAs, and CSLAs with and without the BEC converters by considering 32-bit accurate and approximate additions to facilitate a comparison. For the gate-level implementations, we considered a 32/28 nm complementary metal-oxide-semiconductor (CMOS) process targeting a typical-case process–voltage–temperature (PVT) specification. The results show that the hybrid CLA/RCA architecture is preferable among the CLA and CSLA architectures from the speed and power perspectives to perform accurate and approximate additions.


Author(s):  
Alberto Serena ◽  
Lars E. Bakken

The tip leakage flow affects turbomachines performance generating losses and reducing the effective blading; in addition, unsteady phenomena arise, negatively influencing the machine stability. In this paper, an overview of the existing models is presented. Local measurements of the pressure pulsations, visual flow observations and high quality video recordings from a high speed camera are performed in a novel pump laboratory, which provides the desired visualization of the rotating channels, and allows to study the fluctuating and intermittent nature of this phenomenon, and detect any asymmetry among the channels. A detailed comparison of the vortex tip structure for various tip clearances and with a whole set of numerical simulations finally completes the analysis. The three main focus areas are: tip vortex location, structure and evolution, performance comparison between shrouded and open impeller, at different tip clearance sizes, and study of the rotating instabilities.


2022 ◽  
pp. 1-16
Author(s):  
Nagaraj Varatharaj ◽  
Sumithira Thulasimani Ramalingam

Most revolutionary applications extending far beyond smartphones and high configured mobile device use to the future generation wireless networks’ are high potential capabilities in recent days. One of the advanced wireless networks and mobile technology is 5G, where it provides high speed, better reliability, and amended capacity. 5 G offers complete coverage, which is accommodates any IoT device, connectivity, and intelligent edge algorithms. So that 5 G has a high demand in a wide range of commercial applications. Ambrosus is a commercial company that integrates block-chain security, IoT network, and supply chain management for medical and food enterprises. This paper proposed a novel framework that integrates 5 G technology, Machine Learning (ML) algorithms, and block-chain security. The main idea of this work is to incorporate the 5 G technology into Machine learning architectures for the Ambrosus application. 5 G technology provides continuous connection among the network user/nodes, where choosing the right user, base station, and the controller is obtained by using for ML architecture. The proposed framework comprises 5 G technology incorporate, a novel network orchestration, Radio Access Network, and a centralized distributor, and a radio unit layer. The radio unit layer is used for integrating all the components of the framework. The ML algorithm is evaluated the dynamic condition of the base station, like as IoT nodes, Ambrosus users, channels, and the route to enhance the efficiency of the communication. The performance of the proposed framework is evaluated in terms of prediction by simulating the model in MATLAB software. From the performance comparison, it is noticed that the proposed unified architecture obtained 98.6% of accuracy which is higher than the accuracy of the existing decision tree algorithm 97.1% .


Sign in / Sign up

Export Citation Format

Share Document