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There are a number of things that make RISC-V different from OpenSPARC. One is that OpenSPARC is not a very scalable design, it could probably only ever work in

There are a number of things that make RISC-V different from OpenSPARC. One is that OpenSPARC is not a very scalable design, it could probably only ever work in servers and workstations, and workstations are essentially a monoculture. Another reason is timing: manufacturing processes have effectively stopped yielding performance and power gains as the fundamental constraint (distance between components on chip) doesn't get any smaller. This means that in order to keep the pace up for any popular workload, many new microarchitectures will need to be created. RISC-V is amenable to a wide array of microarchitectural decisions, and doesn't carry the architectural baggage of ARM and MIPS licensing and technical quirks, or the impossible licensing of x86. > But does anyone expect RISC-V to really go head-to-head with Xeon, Opteron, ThunderX, Centriq? Except for Intel, none of these manufacturers have any reason to resist RISC-V. All of these vendors can directly port knowledge from one ISA to another. So really it becomes a matter of "will there be a demand for RISC-V hardware in the server and workstation markets?", and the answer to that is a firm "maybe". I think that today, since most software is written in high level languages which are at least as abstract as C, there is little reason why a new ISA couldn't take hold in any of these markets if hardware vendors can promise good things to ISVs and to customers who write their own software. At present, there is a considerable barrier to entry for new designers and manufacturers to approach ARM, POWER, and MIPS, and basically no hope of manufacturing an AMD64. ARM is not the cuddly RISC architecture people think it is, it is in many ways nearly as quirky as x86, and therefore very expensive to enter and innovate on. Furthermore, it can take more than a year to negotiate an architectural license with ARM, your company or the market might no longer exist by the time you close the deal. POWER is not too far off on licensing, and it's not all that elegant either (though far more surmountable than ARM). MIPS lacks industry momentum and standardized high performance feature sets (wide vector compute, hardware security features), and its custodian company seems to barely acknowledge it exists. All in all, nobody knows if it'll work out, but there are good reasons for RISC-V to succeed in the market. The challenges also seem surmountable.

dom0 10y ago
OpenSPARC is GPL. And OpenSPARC means the T1/T2 designs (high throughput, very low single-threaded performance) which are useless outside their niche.
CalChris 10y ago
> RISC-V is amenable to a wide array of microarchitectural decisions As is ARMv8. Applied Micro, Broadcom, Cavium, Huawei, Nvidia, AMD, Samsung and Apple are all architectural licensees with radically different microarchitectural implementations. For example, Nvidia is Transmeta code-morphing style implementation. Also, Intel and AMD continue to innovate in the x86 space. At this date, RISC-V has no fundamental advantage over any of these architectures and then has the fundamental disadvantage of not having access to their IP. You're lining up against Usain Bolt and your advantage is that you're wearing organic cotton. That's just not gonna work.
- analognoise 10y ago
  " You're lining up against Usain Bolt and your advantage is that you're wearing organic cotton. That's just not gonna work." I'm stealing this as a saying.
- yaantc 10y ago
  You're right, but key words here are "At this date". What you said could have been said exactly in the same way about Linux against commercial Unices about 15 years ago. It's a long game here, and we're only in the early phase. And it may not take that long, but we'll see. Regarding technology, just as Linux initially the key is not having a technological advantage, but being cheaper and good enough. The improvements can come later, when the ecosystem gets bigger and more resources pours in.
  - sweden 10y ago
    RISC-V is thrown around like if it's an already working CPU but it is not. It is just a document describing an ISA, you can't compare it to Linux, it's a completely different thing. There are a lot of costs in implementing an ISA and that includes: design, functional verification, physical implementation and software testing. All those steps together will require hundreds and hundreds of engineers, many expensive tools and thousands of man-hours. And once you are done, you will need to find be careful not to violate any patents while shipping your CPU to the end customer. By paying a license fee to ARM, you get all these steps done for you plus with support. Linux is something that you can download from kernel.org, compile overnight and get it booting right away. RISC-V is something that you need to build yourself.

dom0 10y ago

OpenSPARC is GPL. And OpenSPARC means the T1/T2 designs (high throughput, very low single-threaded performance) which are useless outside their niche.

CalChris 10y ago

> RISC-V is amenable to a wide array of microarchitectural decisions As is ARMv8. Applied Micro, Broadcom, Cavium, Huawei, Nvidia, AMD, Samsung and Apple are all architectural licensees with radically different microarchitectural implementations. For example, Nvidia is Transmeta code-morphing style implementation. Also, Intel and AMD continue to innovate in the x86 space. At this date, RISC-V has no fundamental advantage over any of these architectures and then has the fundamental disadvantage of not having access to their IP. You're lining up against Usain Bolt and your advantage is that you're wearing organic cotton. That's just not gonna work.

analognoise 10y ago
" You're lining up against Usain Bolt and your advantage is that you're wearing organic cotton. That's just not gonna work." I'm stealing this as a saying.
yaantc 10y ago
You're right, but key words here are "At this date". What you said could have been said exactly in the same way about Linux against commercial Unices about 15 years ago. It's a long game here, and we're only in the early phase. And it may not take that long, but we'll see. Regarding technology, just as Linux initially the key is not having a technological advantage, but being cheaper and good enough. The improvements can come later, when the ecosystem gets bigger and more resources pours in.
- sweden 10y ago
  RISC-V is thrown around like if it's an already working CPU but it is not. It is just a document describing an ISA, you can't compare it to Linux, it's a completely different thing. There are a lot of costs in implementing an ISA and that includes: design, functional verification, physical implementation and software testing. All those steps together will require hundreds and hundreds of engineers, many expensive tools and thousands of man-hours. And once you are done, you will need to find be careful not to violate any patents while shipping your CPU to the end customer. By paying a license fee to ARM, you get all these steps done for you plus with support. Linux is something that you can download from kernel.org, compile overnight and get it booting right away. RISC-V is something that you need to build yourself.