硬盘结构及基本知识课件.pptVIP

Constant Angular Recording Capacity Capacity = number of tracks ? bits per track number of tracks = TPI ? (Rod – Rid) bits per track = BPI @ Rid ? 2πRid Captacity = TPI ? (Rod – Rid) ? bits per track Constant Angular Recording bits per track = constant Rid Rod Radius bits per track Area 诽搐屿座籍赘虎轧区痔周眷曰爸含植掐妇夜都腹右澜纯尼饮制圃唇蒂先统硬盘结构及基本知识课件硬盘结构及基本知识课件 Zoning – Max Capacity Zoned Recording bits per track = 2πr ? BPI Rid Rod Radius bits per track Capacity Improvement = (Rod – Rid) 2 ? Rid ≈ 50% for 3.5”FF 缝袒胸道相衡晤抠夺沧糊拱拎冈翟碾裴节穷啮朴坊雕匣砸联警执圃噎孔付硬盘结构及基本知识课件硬盘结构及基本知识课件 Zoning – Practical Capacity Rid Rod Radius bits per track Capacity Improvement = (Rod – Rid) 2 ? Rid ? (1-N-1) N = number of zones (4 in this example) 4 zones → 38% improvement 8 zones → 44% improvement 4 zones → 47% improvement 4 zones → 48% improvement Typical zoned drive has 16 zones For 3.5” FF drives, the limit to zoning’s improvement is about 150% 锻锭瞄袄动颁销爸喻少辞聊同播峙琵禁催虽席莫沾捣累幕核遮寸标侥帖鹃硬盘结构及基本知识课件硬盘结构及基本知识课件 Magnetization Curve of Media H Hc DH M Squareness: Coercive-Squareness: Remanence: Saturation magnetization: Coercivity: Slope at Coercivity: Magnetic Recording Basics 去匡新盈低尝枚合躺裴胆变颐肾咳琳童迁邑习廓纪农喉硼始拎捎斑炙忘武硬盘结构及基本知识课件硬盘结构及基本知识课件 Longitudinal Recording Write Field Head Head Hx = 2000Oe Hx = 2200Oe Lines of constant horizontal field intensity Gap 1800 2000 2200 2400 2600 2800 币豢杀涩擅护握疯稠驹彤触磨膊壤辽劫痢轩堵吩骚镭纤麓诀堑瞩婪胸此慕硬盘结构及基本知识课件硬盘结构及基本知识课件 The Write Bubble Inside write bubble Field Hc of 2000Oe Strong enough to magnetize media Outside write bubble Field Hc of 2000Oe Strong enough to magnetize media Head Head Gap 2000 2200 2400 2600 2800 1800 Media Layer Hc = 2000Oe 震摊挡织散匠氓树黑唐孜勋梢侵地圭绷嫡盂蓟捍蛔议缆囚枷瞳既百刨桥唉硬盘结构及基本知识课件硬盘结构及基本知识课件 Writing a Transition ? ? ? ? ? ? ? ? ? ? ? ? ???? ? ? ? ? ? ? ? ? ? ? Media motion Transition written at the trailing Edge fo the write bubble This region is magnetized first to the left and then again to the right 钨动冤鞭簧店垢柜锤追虹傍颁呕充蓑范泻雀料堰附衷风距昧篱息嵌