Polkadot JAM explained: PVM, cores and 42x data availability
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Breaks down JAM from the Gray Paper, which replaces the Relay Chain with a RISC-V based PVM, 1023 validators and 341 cores. Claims 852Mb/s of DA (42x) and 85x the computation of Polkadot 1.0, enabling CoreChains and ZK rollup settlement.
Key claims
DA capacity of 852Mb/s vs 20Mb/s before async backing and 67Mb/s after
85x computation of Polkadot 1.0, 250-350k TPS before bottlenecks
1023 validators, 3 per core, 341 cores
Polkadot is back and JAM marks the beginning of a new era for $DOT. ⭕️✨
Polkadot is getting a VM! 🤯
Let me break down what this means and how it positions Polkadot in the modular narrative!👇
Polkadot’s Relay Chain is about to be sunset as JAM, a...
„Permissionless, decentralized hybrid system offering smart-contract functionality structured around a secure & scalable in-core/on-chain dualism”
...is coming in to replace it.
JAM is built around 5 core pillars:
✦ Network Resilience
✦ Generalizability (Turing-complete computation)
✦ High Performance
✦ Coherency (interoperability across ecosystem)
✦ Accessibility (permissionless, easy and cheap to use)
The main change is that JAM will allow smart contract functionality (like in Ethereum). JAM uses RISC-V, an open-source instruction set architecture used to develop custom processors for many use cases, which provides the basis for Polka Virtual Machine (PVM).
RISC-V provides great pre-existing tooling for the PVM ecosystem and supports languages like C++ & Rust, while it is perfect for building efficient re-compilers on consumer hardware.
From a tech perspective the key elements are:
✦ Staking: There will be staking mechanism in JAM, however the token remains unknown at this point afaik. DOT? Something new? The latter seems unlikely but who knows.
✦ Safrole: SNARK-based algorithm, that protects validators from DDoS attacks & manages how blocks are added to the chain.
✦ Grandpa: The Polkadot finality gadget.
The network is expected to have 1023 validators with 3 validators per core. This amounts to 341 cores across the network. Cores are the key infra JAM runs on and "coretime" is the unit through which blockspace is allocated. In computing terms, it's the data availability and execution time of a core. Agile Coretime (like in Polkadot) allows builders to only pay for the resources they need.
But let's talk Data Availability on Polkadot:
✦ Before Asynchronous Backing 20Mb/s
✦ After Asynchronous Backing 67Mb/s
✦ JAM 852Mb/s
JAM will have 42x more data availability capacity and thanks to handling computation in a parallelized manner over a scalable node network, a proposition pioneered by Polkadot, JAM will handle 85x the computation load compared to Polkadot 1.0. This means JAM could achieve 250-350k TPS before even encountering any bottleneck issues. That's not a hard limit though with the network capable of scaling beyond 1.5M TPS in the long-term as the ecosystem matures.
Polkadot in the Modular Stack:
So basically, JAM combines the programmability of Ethereum with the scalability of @Polkadot. This highly scalable base layer works perfectly with Elastic Scaling coming on Polkadot, where projects will be able to add multiple cores for one task, shorten block production time or add on-demand cores if they run into throughput issues.
JAM enables a broad design space of application- and vertical-specific network designs referred to as CoreChains that leverage JAM's powerful DA capability, high throughput and fast finality.
Considering the crypto-economic security at stake here as well, can serve as very strong base layer for ZK rollups for example that:
✦ Leverage JAM as a settlement as elastically scalable settlement layer that provides strong security & liveness guarantees.
✦ Use the underlying Polkadot architecture as a scalable, decentralized and potentially shared sequencer (based sequencing).
✦ Rely on the enormous DA capacity of JAM to publish transaction/state data to a crypto-economically secured base layer.
All in all this sounds pretty cool and CoreChains are definitely an interesting concept I will be watching.
Kind of feels like @Polkadot, which has always been a pioneer on modularity (even tho little recognized) is now going fullsend on the modular narrative, serving it across multiple verticals in the stack.
DYOR anons! 🔍
QUOTING @gavofyork
Happy to release the initial Jam spec in the Gray Paper (10 years after my release of the Yellow Paper): A proposal for the future of @Polkadot. t.co/thL6CSNGUp
Happy to release the initial Jam spec in the Gray Paper (10 years after my release of the Yellow Paper): A proposal for the future of @Polkadot. t.co/thL6CSNGUp
What came next · since 19 Apr 2024
Show how the covered asset moved
This explainer walks through how things work without making a call on the token, so price moves since publication are shown as market context.
Covered, no call
Since then
Zero has written 6 more pieces on Polkadot and $DOT since this one.
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