This article consists of a collection of slides from the author's conference presentation on the special features, system design and architectures, processing capabilities, and targeted markets for NVIDIA's Denver family of processors.

This paper introduces a technique which leverages value prediction and multithreading on a simultaneous multithreading processor to achieve higher performance in a single threaded application. By allowing the value-speculative execution to proceed in a separate thread, this technique overcomes barriers that make traditional value prediction relatively ineffective for tolerating long latency loads. It shows that this technique can be as much as 2-5 times more effective than traditional value prediction, achieving more than 40% average performance gain on the SPEC benchmarks with realistic hardware parameters. These gains come from two effects: allowing greater separation between the stalled load and the speculative execution, and the ability to speculate on multiple values for a single load.

Intrusion detection systems (IDSs) have become widely recognized as powerful tools for identifying, deterring and deflecting malicious attacks over the network. Essential to almost every intrusion detection system is the ability to search through packets and identify content that matches known attacks. Space and time efficient string matching algorithms are therefore important for identifying these packets at line rate. We examine string matching algorithms and their use for intrusion detection, in particular, we focus our efforts on providing worst-case performance that is amenable to hardware implementation. We contribute modifications to the Aho-Corasick string-matching algorithm that drastically reduce the amount of memory required and improve its performance on hardware implementations. We also show that these modifications do not drastically affect software performance on commodity processors, and therefore may be worth considering in these cases as well.

Buffer overflow vulnerabilities are currently the most prevalent security vulnerability; they are responsible for over half of the CERT advisories issued in the last three years. Since many attacks exploit buffer overflow vulnerabilities, techniques that prevent buffer overflow attacks would greatly increase the difficulty of writing a new worm. This paper examines both software and hardware solutions for protecting code pointers from buffer overflow attacks. We first evaluate the performance overhead of the existing Point-Guard software solution for protecting code pointers, and show that it can be applied using binary modification to protect return pointers on the stack. These software techniques guard against write attacks, but not read attacks, where an attacker is attempting to gain information about the pointer protection mechanism in order to later mount a write buffer attack. To address this, we examine encryption hardware to provide security for code pointers from read and write attacks. In addition, we show that pure software solutions can degrade program performance, and the light-weight encryption hardware techniques we examine can be used to provide protection with little performance overhead.