Power Is Killing Your Product: When ASIC Beats FPGA on Efficiency

Power problems rarely show up as a single failure.

They appear as small compromises: a bigger battery, a thicker enclosure, a thermal pad, a lower clock speed, a disabled feature. Each compromise feels manageable. Over time, they shape the product in ways no one originally intended.

For many teams, power is the first real signal that FPGA is no longer the right platform.

This article explains why FPGA power efficiency stops scaling, when ASIC becomes the only realistic option, and how to recognize the moment before power quietly kills your product roadmap.

Why FPGA power looks acceptable early on

FPGA power inefficiency is easy to ignore at the beginning.

Early products are often:

• Plug-powered
• Over-cooled
• Lightly utilized
• Built to prove functionality, not efficiency

At this stage, power is “good enough”. The FPGA works, schedules move forward, and optimization feels optional.

The problem is that FPGA power scales poorly as products mature.

Where FPGA power breaks down

As products evolve, usage patterns change.

More features run simultaneously. Duty cycles increase. Customers expect longer battery life or quieter systems. Suddenly, power becomes a constraint instead of a detail.

Common breaking points include:

• Battery life targets that can’t be met without hardware changes
• Thermal limits that force throttling or mechanical redesign
• Power budgets that block additional features
• Regulatory or environmental constraints

At this point, software and RTL optimizations deliver diminishing returns.

Why FPGA is fundamentally inefficient

FPGA power inefficiency is not a bug. It is structural.

FPGA architectures trade efficiency for flexibility:

• Configurable routing adds capacitance
• General-purpose logic replaces optimized datapaths
• Clock networks are heavier and less specialized

These costs are acceptable when flexibility matters more than efficiency. They become prohibitive when efficiency becomes the product differentiator.

No amount of optimization can remove this structural overhead.

What ASIC changes in the power equation

ASIC removes the flexibility tax.

By tailoring logic, memory, clocking, and power domains to the exact workload, ASIC can achieve:

• Lower dynamic power per operation
• Reduced leakage through optimized libraries
• Fine-grained power gating
• Custom clocking strategies

The result is not incremental improvement. It is often orders of magnitude better energy efficiency compared to FPGA implementations of the same function.

Power problems often hide larger issues

Teams often frame the problem as “power optimization”.

In reality, power pressure usually signals deeper misalignment:

• The architecture is stable enough to justify specialization
• The product is shipping or about to ship at scale
• Efficiency now matters more than flexibility

At this stage, continuing on FPGA is not a neutral decision. It is a strategic choice to accept recurring cost, size, and performance penalties.

When ASIC becomes the only realistic option

ASIC does not make sense for every product.

But it becomes difficult to avoid when:

• Power directly limits user experience
• Battery size or cooling defines the product form factor
• Efficiency is a competitive differentiator
• Feature growth is blocked by power headroom

These conditions rarely reverse themselves.

The mistake teams make

The most common mistake is waiting until power issues are obvious to everyone.

By then:

• Mechanical changes are already baked in
• Customer expectations are set
• Competitors may have moved earlier

The goal is not to jump into ASIC prematurely.

The goal is to recognize when power efficiency has become non-negotiable.

What to do next

If power is shaping your product decisions, it is time to step back and ask a simpler question.

Does ASIC make sense for this product now, later, or not at all?

That question should be answered before spending more time on incremental FPGA optimization.

Next step

Run the 2-minute ASIC or Not? Decision Wizard to get a clear, non-sales recommendation based on power, volume, and readiness.

👉 /asic-or-not