NASDAQ: HILL April 2015NASDAQ: HILL1 Hanif Jamal, CFO, Dot Hill

2014 Key Financial Metrics DOT HILL 2014 FINANCIAL RECAP (NON-GAAP) April 2015NASDAQ: HILL2 2014YoY Change Total Revenue ($M) % Vertical Markets % Server OEM % Gross Margin (%) 33.6%+ 80 bps Operating Expenses ($M) M (4%) Operating Margin (%) 5.9%+ 80 bps Operating Profit ($M) M (21%) Operating Leverage (%) 25.0%n/a EPS ($) $0.20+ $0.02 (11%) Net Working Capital ($M) M (18%) Net Working Capital = Current Assets – Current Liabilities Operating Leverage = Change in Operating Profit / Change in Revenue

FINANCIAL PROGRESS (NON-GAAP) April 2015NASDAQ: HILL3

FINANCIAL PROGRESS (NON-GAAP) April 2015NASDAQ: HILL4

FINANCIAL PROGRESS SUMMARY April 2015NASDAQ: HILL5

GUIDANCE Q1’15 AND 2015 April 2015NASDAQ: HILL6 Q1’15 Updated Non-GAAP Guidance Q1 ’15E YoY Change (at Midpoint) Total Revenue ($M) 60.0 – % Vertical Markets + 60% Server OEM - 8% EPS ≈ $0.06+ $0.04 (+ 200%) 2015 Non-GAAP Guidance Reiteration 2015E YoY Change (at Midpoint) Total Revenue ($M) 230 – % Vertical Markets 120 – % Server OEM 110 – 120Flat Gross Margin 33 – 34%Flat Operating Expenses ($M) 61 – 64+ 4% EPS $ $ % Q4’14 momentum projected to continue through 2015 Q1’15E based on guidance issued April 16, 2015 and 2015E based on guidance issued March 5, 2015

HISTORICAL AND PROJECTED DIVERSIFICATION April 2015NASDAQ: HILL7

HISTORICAL AND PROJECTED GROSS MARGIN April 2015NASDAQ: HILL8

HISTORICAL AND PROJECTED OPERATING EXPENSES (NON-GAAP) April 2015 NASDAQ: HILL 9

OPERATING LEVERAGE & MARGINS April 2015NASDAQ: HILL10

NEW CUSTOMER ECONOMICS April 2015NASDAQ: HILL11 Target New Customer Margin Model by Annual Revenue Potential <$3M$3-20M$20-50M$50M+ Vertical Markets Gross Margin % 45%40%35%30% Opex % 25%12%10%8% Contribution Margin % 20%28%25%22% Server OEMs Gross Margin % 40%35%30%25% Opex % 18%10%6%4% Contribution Margin % 22%25%24%21%

Target New Customer Margin Model by Annual Revenue Potential <$3M$3-20M$20-50M$50M+ Vertical Markets Gross Margin % 45%40%35%30% Opex % 25%12%10%8% Contribution Margin % 20%28%25%22% Server OEMs Gross Margin % 40%35%30%25% Opex % 18%10%6%4% Contribution Margin % 22%25%24%21% NEW CUSTOMER ECONOMICS April 2015NASDAQ: HILL12 Scenario #1 Achieve $100M of growth beyond 2015 over two years, from 1 or 2 Vertical Markets customers Scenario #1 Achieve $100M of growth beyond 2015 over two years, from 1 or 2 Vertical Markets customers

Target New Customer Margin Model by Annual Revenue Potential <$3M$3-20M$20-50M$50M+ Vertical Markets Gross Margin % 45%40%35%30% Opex % 25%12%10%8% Contribution Margin % 20%28%25%22% Server OEMs Gross Margin % 40%35%30%25% Opex % 18%10%6%4% Contribution Margin % 22%25%24%21% NEW CUSTOMER ECONOMICS April 2015NASDAQ: HILL13 Scenario #2 Achieve $100M of growth beyond 2015 over two years, from potentially Vertical Markets customers Scenario #2 Achieve $100M of growth beyond 2015 over two years, from potentially Vertical Markets customers

Target New Customer Margin Model by Annual Revenue Potential <$3M$3-20M$20-50M$50M+ Vertical Markets Gross Margin % 45%40%35%30% Opex % 25%12%10%8% Contribution Margin % 20%28%25%22% Server OEMs Gross Margin % 40%35%30%25% Opex % 18%10%6%4% Contribution Margin % 22%25%24%21% NEW CUSTOMER ECONOMICS April 2015NASDAQ: HILL14 Scenario #3 Achieve $100M of growth in Vertical Markets beyond 2015 over two years, with $50M from one customer, $30M from one customer and $20M from two customers Scenario #3 Achieve $100M of growth in Vertical Markets beyond 2015 over two years, with $50M from one customer, $30M from one customer and $20M from two customers

SENSITIVITY OF $100M IN INCREMENTAL REVENUE April 2015NASDAQ: HILL15 Business Model Sensitivity Analysis 2015 Midpoint Guide Scenario #1Scenario #2Scenario #3 Revenue ($M) Gross Margin % 33.0%32.5%36.8%33.5% Operating Expenses ($M) Operating Expense % 25.0%21.0%25.9%21.4% Operating Profit ($M) Operating Margin (%) 8.0%11.5%10.9%12.1% Scenario #3 achieves balance between operating margin, revenue diversification and execution risk. Assumes 2.5% annual increase in base operating expense or $3M over 2 years, plus incremental new customer related spend

TARGET BUSINESS MODEL April 2015NASDAQ: HILL16 Business Model Our target business model remains fundamentally unchanged with 14-18% growth rates in total revenue, but we have increased our operating margin goals from 8-12% to 10-13% Revenue Growth vs Baseline (CAGR) Vertical Markets Growth vs Baseline (CAGR) Server OEM Growth vs Baseline (CAGR) Gross Margin % Operating Expense Goal as % of Revenue Operating Margin % 2015 Midpoint Midpoint 15% 32% Flat 33% 25% 8.0% 2017 Operating Model Framework LowHigh 14%18% 25%35% -10%10% 33%34% 23.0%21.0% 10%13%

GROWTH THROUGH INNOVATION April 2015NASDAQ: HILL17 Profit Without GrowthGrowth Without Profit GROWTH and Accelerating PROFITABILITY

QUESTIONS? April 2015NASDAQ: HILL18

NASDAQ: HILL April 2015NASDAQ: HILL19 Charles Christ, Chairman of the Board, Dot Hill

APPENDIX 1 Reconciliation of GAAP to Non-GAAP Financial Measures April 2015NASDAQ: HILL20

APPENDIX I: RECONCILIATION OF GAAP TO NON- GAAP FINANCIAL MEASURES

April 2015NASDAQ: HILL GAAP TO NON-GAAP REVENUE RECONCILIATION ($K) Note: Totals may not aggregate due to rounding

April 2015NASDAQ: HILL GAAP TO NON-GAAP GROSS PROFIT RECONCILIATION ($K, EXCEPT %) Note: Totals may not aggregate due to rounding

April 2015NASDAQ: HILL GAAP TO NON-GAAP OPERATING EXPENSES RECONCILIATION ($K)

April 2015NASDAQ: HILL GAAP TO NON-GAAP NET INCOME (LOSS) RECONCILIATION ($K) Note: Totals may not aggregate due to rounding

April 2015NASDAQ: HILL GAAP TO NON-GAAP EPS (LPS) RECONCILIATION Note: Totals may not aggregate due to rounding

April 2015NASDAQ: HILL GAAP TO NON-GAAP SERVER OEM RECONCILIATION ($K) Note: Totals may not aggregate due to rounding

April 2015NASDAQ: HILL GAAP to Non-GAAP Server OEM Reconciliation ($K) (continued) Note: Totals may not aggregate due to rounding

April 2015NASDAQ: HILL GAAP TO NON-GAAP VERTICAL MARKETS RECONCILIATION ($K) Note: Totals may not aggregate due to rounding

April 2015NASDAQ: HILL GAAP TO NON-GAAP VERTICAL MARKETS RECONCILIATION ($K) (CONTINUED)