Dit doet er echt wel toe het gaat niet alleen over bandbreedte.
De standaard is compatibel met de vorige en als gamer merk je daar misschien niet veel van. Omdat bepaalde features niet gebruikt worden in games. Maar je hebt een enorme verbetering in signaal integriteit en een hoop extra features die voor AI, gaming en (semi) professionele workloads en applicaties echt wel een meerwaarde kunnen hebben en zijn.
Bijvoorbeeld de Compute eXpress Link technology, die bouwt op de PCIe 5.0 standaard en CXL dan o.a. de Coherent Accelerator Processor Interface (CAPI) ondersteunt "designed to be layered on top of PCI Express, for directly connecting central processing units (CPUs) to external accelerators like graphics processing units (GPUs), ASICs, FPGAs or fast storage. It offers low latency, high speed, direct memory access connectivity between devices of different instruction set architectures." Ook alle nieuwe en geavanceerde geheugentechnieken zoals AMD 3D V-Cache en de Infinity Fabric hebben speciale ondersteuning hiervoor. Ik kan nog even blijven door gaan hoor ...
Je kan zelf de voordelen of specificatie van 5.0 opzoeken. Maar ik zal de basis hier neerzetten, aangezien je voor de volle officiële specs een account nodig hebt.
https://pcisig.com
What new capabilities and features does PCIe 5.0 add in addition to increased bit rate?
As with prior generations, PCIe 5.0 adds some new optional capabilities and features. These include:
Alternate protocol support – This feature allows non-PCIe protocols to be based on the high-performance and robust PCIe PHY layer. This allows such protocols to be developed much more quickly.
Bypass Link equalization options – Two equalization bypass options are added: No Equalization Needed, and Equalization Bypass to Highest Data Rate. These bypass options can be used to reduce the time needed to bring up a PCIe Link to its highest data rate at start-of-day.
Precoding – Added to avoid LCRC/CRC aliasing for cases where a received clock-like bit pattern can lead to contiguous burst errors.
Component Measurement and Authentication (CMA) – Added to PCIe 5.0 by way of an Engineering Change Notice (ECN), CMA provides the mechanisms to perform security exchanges with a component or a Device Function. This capability, for example, provides the means to establish the hardware and firmware identities of a Function before assigning it to a Virtual Machine.
Integrity and Data Encryption (IDE) – Added to PCIe 5.0 by way of an ECN, this capability provides confidentiality and integrity protection for communications between two Ports connected through one or more PCIe Links.
What is Precoding and why is it needed?
For certain Decision Feedback Equalizer (DFE) settings, certain received bit patterns, such as clock patterns, can cause contiguous burst errors, which in turn can cause LCRC/CRC aliasing. Precoding involves XORing the current bit with the previous bit. That has the effect of converting long contiguous burst errors into two random bit flips that can be reliably detected by CRC. PCIe 5.0 adds the ability for Link partners to request precoding at data rates where one partner or the other requires it.
Retimers were introduced with PCIe 4.0. Up to two Retimers are allowed between the Upstream Port and the Downstream Port of a Link. They are used when necessary to reliably extend the achievable channel length between two PCIe Ports. PCIe 4.0 and PCIe 5.0 Retimers are Physical Layer protocol aware. That is, they participate in Link Equalization, and they adjust their data rate of operation and their Link width in concert with the Upstream and Downstream Ports of the Link
Edit Die kaarten zijn ook niet alleen "gamer kaarten" meer. Als je ze zo gebruikt dan zijn het natuurlijk heel duren GPU's (waar iedereen over klaagt).
[Reactie gewijzigd door sam1987 op 28 september 2024 01:20]