😉 TbredA only runs cooler but doesn't o/c better than Polly, hence XP2200+. TbredB not only runs cooler but should hit XP2800+ type speeds. IIRC Polly's are pigs to unlock, TbredA's are pretty easy and TbredB's are unlocked! If your CPU is marked AXDA1800DUT3C @ 1.60v you have TbredB (CPUID 6-8-1). Anyway, PC2100 is all you need unless your CPU hits XP2400+ type speeds, try unlocking and using the multiplier to keep FSB & RAM stock, it may not be worth investing cash in PC2700.