The 2024 Object Cache Performance Showdown

Object caching is one of the highest-leverage optimizations available to WordPress sites running WooCommerce at scale. In this benchmark study, we put Redis and Memcached head-to-head under realistic, synthetic load conditions to determine which solution delivers superior performance for high-traffic stores.

Test Methodology

All tests were conducted on isolated Bare Metal instances (Ryzen 9 5950X, 128GB ECC RAM) running WooCommerce 8.x with a 10,000-product catalog. We simulated 500 concurrent users executing full checkout flows over a 72-hour window to account for cold cache scenarios and noisy-neighbor effects in shared environments.

Results: TTFB Comparison

Redis outperformed Memcached by an average of 23% in TTFB reduction across all WooCommerce page types. The most significant gains were observed on cart and checkout pages, where Redis object persistence reduced database roundtrips by up to 68%.

Key Findings

• Redis: avg TTFB 82ms, p95 141ms — ideal for persistent session data
• Memcached: avg TTFB 107ms, p95 198ms — simpler setup, lower memory overhead
• Under sustained 500-user load, Redis cache hit rate held at 98.2% vs Memcached 94.7%
• Both solutions eliminated approximately 85% of redundant database queries vs no-cache baseline

Recommendation

For WooCommerce stores handling more than 1,000 daily transactions, Redis is the clear recommendation. Its persistence layer and superior connection handling under concurrency make it significantly more resilient. Memcached remains a viable option for simpler WordPress sites where setup complexity is a primary concern.

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